LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 

Class 


THE  EARTH  IN  PAST  AGES 


BY 

SOPHIE  BLEDSOE  HERRICK 

AUTHOR    OF     "  CHAPTERS    ON    PLANT    LIFE  "    ETC. 


NEW  YORK    •:•    CINCINNATI    •:•    CHICAGO 

AMERICAN    BOOK    COMPANY 


Copyright,  1888,  by  HARPER  &  BROTHERS. 

Ail  rightt  reierved. 
W.   P.    9 


CONTENTS. 


I.  WHAT  is  GEOLOGY  ? 1 

II.  THE  CLEW  FOUND  IN  THE  ROCKS 8 

III.  WATER '. ,20 

'  IV.  THE  REIGN  OF  FIRE 34 

V.  FIRE  AND  WATER 47 

VI.  THE  ICE-KING  AT  WORK 60 

VII.  PLANTS  AS  BUILDERS 73 

VIII.  THE  BUILDERS  UNDER  THE  SEA 86 

IX.  THE  CRUST  OF  THE  EARTH 97 

X.  MOUNTAIN-BUILDING 105 

XI.  METALS  AT  HOME 115 

XII.  A  STUDY  OF  BONES 129 

£111.  THE  DAWN  OF  LIFE .  135 

XIV.  THE  REIGN  OF  FISHES 145 

XV.  THE  REIGN  OF  PLANTS 154 

XVI.    "STRIKING  OIL" .   167 

XVII.  SALT 178 

XVIII.  THE  REIGN  OF  REPTILES 184 

XIX.  THE  BOTTOM  OF  THE  SEA 198 

XX.  BIRDS  OF  THE  PAST 208 

XXI.  THE  REIGN  OF  LAND  MONSTERS 220 

XXII.  THE  COMING  OF  MAN  ....  .230 


196435 


ILLUSTEATIONS. 


PIG.  PAGE 

1.  SLAB  OF  RIPPLE-MARKED  SANDSTONE 10 

2.  SHELL  IN  THE  ROCK  (Ammonite) 11 

3.  FERN-LEAF  IN  STONE 12 

4.  TILTED  LAYERS  IN  THE  ROCK 13 

5.  SHELLS  IN  BROKEN  ROCK 15 

6.  LEVEL  AND  LIFTED  LAYERS 17 

7.  STRATIFIED  ROCK  CLIFFS  AT  BROUGH 23 

8.  THE  CLETT,  HOLBORN  HEAD,  SCOTLAND 27 

9.  "  THE  CATHEDRAL,  "  LURAY  CAVES,  VIRGINIA 31 

10.  ROCK  VEINS 37 

11.  SECTION  OF  THE  EARTH'S  CRUST 38 

12.  WHITE  CRYSTALS  OF  FELDSPAR 39 

13.  SCORIACEOUS  LAVA 39 

14.  GRAPHIC  GRANITE 40 

15.  GRAPHIC  GRANITE 40 

16.  SANTORIN 43 

17.  FINGAL'S  CAVE 48 

18.  TEMPLE  OF  SERAPIS 51 

19.  CARBONATED  SPRINGS 55 

20.  A  GEYSER 57 

21.  A  GLACIER 61 

22.  ROCK  SCRATCHED  BY  GLACIER 68 


vi  Illustrations. 

FIG.  PAGE 

23.  TRANSPORTATION  OF  ROCKS  BY  GLACIERS 69 

24.  A  TROPICAL  MORASS 75 

25.  MINING  FOR  CEDAR  LOGS  IN  NEW  JERSEY 81 

26.  SECTION  OF  CLIFF 83 

27.  ATOLL 87 

28.  CORAL  WITH  POLYPS 89 

29.  CORALS 91 

30.  CORALS 92 

31.  MAGNESIAN  LIMESTONE 95 

32.  FOSSILS  OF  CHALK   .....' 95 

33.  FOSSILS  OF  CHALK 96 

34.  35.  RAIN-DROPS  AND  WORM-TRACKS  ON  GREEN  SHALE  .    .  100 

36.  A  DISTORTED  SHELL 101 

37.  SEA-WORM  ON  OYSTER-SHELL ....  102 

38.  STRATIFICATION,  JOINTS,  AND  CLEAVAGE 10o 

39.  SECTION  ILLUSTRATING  THE   STRUCTURE  OF  THE  Swiss 

JURA 106 

40.  WRINKLED  LAYERS 107 

41.  PYRAMID  MOUNTAIN     .    .    . 109 

42.  A  CANON Ill 

43.  FAULTS 113 

44.  SCENE  AT  AN  IRON  MINE 117 

45.  PLACER  MINING 121 

46.  HYDRAULIC  MINING 125 

47.  EOZOON  CANADENSE 137 

48.  SEA-WEEDS  AND  SEA  ANIMALS 140 

49.  SILURIAN  SEA-WEED 141 

50.  STAR-FISH 142 

51.  TRILOBITES 142 

52.  CORALS 143 

53.  WING-FISH    .  .  148 


Illustrations.  vii 

FIG.  PAGB 

54.  MAILED  FISHES 149 

55.  SCALES 150 

56.  UNILOBED  TAIL 151 

57.  BILOBED  TAIL 151 

58.  STONE-LILIES 151 

59.  PSILOPHYTON 152 

60.  IDEAL  LANDSCAPE  OF  THE  COAL  PERIOD 157 

61.  COAL  FERNS 159 

62.  TREE-TRUNKS  FOUND  IN  A  MINE 161 

63.  SLAB  OF  SANDSTONE  SHOWING  FOOTPRINTS  OF  SAURIANS  .  165 

64.  OIL  POOL  UNDER  THE  EARTH 171 

65.  OIL  REFINERY,  SHOWING  TANK  CARS .  173 

66.  A  FIELD  OF  DERRICKS.— EFFECT  OF  A  TORPEDO     .     .     .176 

67.  SLAB  OF  SANDSTONE,  WITH  TRACKS  OF  BIPEDS    ....  186 

68.  IDEAL  LANDSCAPE  OF  THE  AGE  OF  REPTILES 189 

69.  THE  PTERODACTYL 191 

70.  RAMPHORHYNCUS — ONE-QUARTER  NATURAL  SIZE  .    .    .    .192 

71.  ICHTHYOSAURUS  AND  PLESIOSAURUS 193 

72.  TRACKS  OF  LABYRINTHODON 195 

73.  CHALK  CLIFFS  OF  DOVER 200 

74.  ENGLISH  CHALK 201 

75.  ATLANTIC  DREDGING 201 

76.  ECHINUS  (Fossil  Sea-urchin) 204 

77.  CORALS  OF  CHALK 205 

78.  TURRILITE.— SCAPHITE 205 

79.  SPONGE  OF  CHALK 206 

80.  BIRD-LIKE  REPTILE 210 

81.  TAIL  AND  FEATHER  OF  REPTILE-LIKE  BIRD,  WITH  TAIL 

OF  MODKRN  BIRD  FOR  COMPARISON 212 

82.  SKELETON  IN  STONE  OF  REPTILE- LIKE  BIRD 213 

83.  THE  EARLIEST  BIRD  (Archaopteryx) .  215 


viii  Illustrations. 

FIG.  PAGE 

84.  NEW  ZEALAND  BIKD,  LATELY  EXTINCT 218 

85.  DINOTHERIUM 221 

86.  MAPLE  LEAF 224 

87.  INSECT  FOUND  IN  ROCK 225 

88.  BUTTERFLY  FOUND  IN  ROCK     . *   .    ,  226 

89.  SKELETON  OF  MEGATHERIUM 228 

90.  SKELETON  OF  MYLODON 229 

91.  THE  IRISH  ELK  COMPARED  WITH  MAN 235 

92.  THE  HAIRY  MAMMOTH 237 

93.  PREHISTORIC  MAN    ,  .  239 


THE  EARTH  IN  PAST  AGES. 


CHAPTER  I. 

WHAT  IS   GEOLOGY? 

GEOLOGY  is  the  history  of  the  earth  and  of  the  vari- 
ous kinds  of  plants  and  races  of  animals  that  have 
lived  upon  it.  This  history  is  not  written  in  books — 
there  were  no  human  beings  living  to  write  them — 
but  it  is  recorded  upon  the  rocks  in  various  ways. 
In  places  sand  rippled  by  the  tide  has  been  covered 
over  and  preserved  till  it  has  hardened  into  stone. 
This  is  just  as  plain  a  story  of  some  far-off  day  when 
a  sandy  beach  lay  along  the  sea  and  the  incoming 
water  threw  it  into  ridges,  such  as  you  may  see  upon 
our  sea-coast  to-day,  as  if  some  one  had  seen  it  and 
written  down  a  description  of  what  he  saw.  In 
other  places  a  piece  of  sandstone  is  pitted  with  holes 
made  by  a  pelting  rain.  It  does  not  need  any  written 
word  to  tell  us  when  we  find  such  a  bit  of  rock  that 
1 


2  The  Earth  in  Past  Ages. 

there  were  rain-storms  in  those  days.  Here  rocks  are 
tilted  up  and  broken,  showing  some  great  force  under- 
neath ;  and  there  they  are  rounded  and  worn,  showing 
the  action  of  water  or  ice.  In  the  midst  of  a  mass  of 
rock  laid  open  by  the  blow  of  a  hammer  we  find  deli- 
cate sea -weed,  with  every  marking  on  the  leaves  as 
plain  as  if  they  had  been  pressed ;  or  we  may  find  in 
such  a  layer  of  rock  laid  open  an  exquisite  shell  or 
starfish.  What  need  do  we  have  of  words  to  tell  us 
that  when  that  rock  was  only  a  sandy  sea-bottom 
these  plants  and  animals  had  sunk  in  the  water,  were 
covered  over  by  new  settlings  of  sand,  and  so  pre- 
served as  you  might  preserve  a  shell  in  plaster  of 
Paris,  and  that  the  sand  had  afterwards  turned  into 
sandstone  ? 

There  is  this  one  thing  that  the  world  has  learned 
very  slowly  to  do,  and  that  is  to  look  honestly  at  nat- 
ure to  see  what  is  there,  and  then  to  use  their  com- 
mon-sense in  finding  out  the  true  meaning  of  what  is 
seen. 

In  the  land  of  Egypt,  for  thousands  of  years,  there 
have  been  lying,  half  buried  in  the  sand,  curious  rocks, 
and  temples  covered  all  over  with  markings  that  no 
one  could  read.  Tall  monoliths,  with  strange  charac- 


What  is  Geology  f  3 

ters  carved  upon  them,  pierced  the  blue  and  rainless 
air,  offering  their  riddle  to  be  guessed,  but  no  one  was 
able  to  read  it.  If  you  ever  go  to  the  Central  Park  in 
New  York,  you  will  see  one  of  these  monoliths,  called 
Cleopatra's  Needle,  that  stood  for  thousands  of  years 
in  Egypt  unread.  Less  than  a  hundred  years  ago  a 
Frenchman  named  Champollion  made  a  study  of  these 
signs.  He  worked  long  over  them,  and  by  the  aid  of 
a  famous  stone  called  the  Rosetta  Stone,  which  had 
upon  it  an  inscription  in  three  different  languages,  he 
discovered  the  clew  to  the  signs  on  the  stones,  and  at 
last  could  read  them ;  and  from  what  he  found  there 
he  was  able  to  write  a  history  of  the  past  in  Egypt  in 
a  language  that  can  easily  be  read. 

In  the  same  way  these  other  strange  writings  upon 
the  rocks,  the  shells  and  leaves  and  bones,  left  there 
by  a  life  long  passed  away,  had  been  noticed  and 
thought  queer,  but  had  never  been  interpreted.  Ovid, 
a  Roman  poet  who  lived  in  the  days  of  Christ,  tells 
us  that  he  had  seen  shells  on  the  mountain-tops,  and 
land  made  by  the  action  of  the  sea.  The  first  person 
who  ever  gave  to  the  world  a  true  explanation  of  these 
things  was  the  great  painter  Leonardo  da  Vinci.  He 
lived  four  hundred  years  ago,  and  you  have  probably 


4:  The  Earth  in  Past  Ages. 

seen  some  engravings  from  his  celebrated  paintings, 
"  The  Last  Supper "  and  "  Mona  Lisa."  A  hundred 
years  later  another  artist,  Bernard  Palissy,  published 
a  book  in  which  he  said  that  the  "  figured  stones,"  as 
he  called  them,  were  the  remains  of  beings  that  had 
once  been  alive  and  had  been  preserved  in  the  sea- 
bottom.  It  is  rather  curious  that  these  two  men  were 
not  men  of  science.  They  were  artists,  who  had 
trained  their  eyes  to  see  and  their  minds  to  think 
about  what  they  saw.  For  two  centuries  after  this 
clew  was  offered  them,  the  so-called  men  of  science- 
went  groping  about  in  the  darkness,  making  foolisl: 
guesses  and  still  more  foolish  arguments. 

Other  people  since  the  days  of  Ovid  have  found  sea- 
shells  upon  the  tops  of  mountains,  and  have  explained 
their  presence  in  various  ways.  For  a  long  time  the 
-Deluge  was  made  to  account  for  anything  out  of 
place  in  creation.  When  the  shells  and  sea -plants 
and  animal  skeletons  were  buried  under  hundreds  of 
feet  of  rock,  the  Deluge  was  given  up,  and  other  ideas 
were  adopted. 

In  Greece,  elephants'  bones  were  supposed  to  be  the 
bones  of  their  old  heroes ;  and  Ajax,  one  of  the  war- 
riors whom  Homer  tells  about,  was  calculated,  from  a 


What  is  Geology?  5 

fossil  knee-bone,  to  have  been  twenty  feet  high.  The 
early  history  of  all  nations  is  full  of  stories  of  drag- 
ons and  giants  and  terrible  monsters.  These  stories 
probably  rose  from  the  finding  of  immense  or  curious 
bones  unlike  those  of  any  animal  living  at  the  time. 

After  these  stories  and  legends  came  to  be  doubted, 
the  bones  still  were  there  to  be  accounted  for.  Some 
writers  called  them  "  freaks  of  nature."  One  brought 
forward  a  very  queer  idea ;  he  said  that  before  God 
created  the  animals,  he  made  a  great  many  models 
and  stored  them  in  the  earth  (as  models  of  machines  are 
stored  in  the  Patent  Office  at  Washington).  Among 
these  models  are  as  many  " failures"  as  among  the 
patents,  apparently,  for  they  were  never  followed  by 
living  animals.  Of  the  shells  found  far  away  from 
water,  it  was  said,  as  late  as  a  century  ago,  that  they 
had  been  brought  from  Rome  or  the  Holy  Land  by 
pilgrims,  and  dropped  far  inland  or  on  the  tops  of 
mountain-peaks. 

But  the  world  was  not  to  be  hoodwinked  forever 
by  such  foolish  suppositions.  As  the  facts  became 
more  and  more  in  number,  the  common-sense  view  of 
the  subject  grew,  and  this  nonsense  became  less  be- 
lieved. It  was  quite  two  hundred  years  after  Leo- 


6  The  Earth  in  Past  Ages. 

nardo  had  explained  the  meaning  of  fossils  before  the 
world  generally  accepted  his  explanations  and  learned 
to  read  the  riddle  of  the  earth  aright. 

Geology  is  not  an  old  science.  It  is  scarcely  one 
hundred  years  old  to-day.  And  some  things  are  still 
unsettled  and  others  unknown;  but  there  are  many 
things  which  are  perfectly  fixed  and  known,  and 
about  the  rest  we  are  learning  every  day. 

What  I  want  you  especially  to  bear  in  mind  is,  that 
the  causes  which  in  the  past  have  built  up  the  crust 
of  the  earth,  and  have  formed  its  continents  and  isl- 
ands, systems  of  lakes  and  systems  of  mountains, 
are  the  very  same  that  are  working  like  changes 
now.  Apart  from  the  work  of  man,  they  are  the 
same,  though  less  violent,  as  time  goes  on.  If  you 
use  your  eyes,  you  can  often  see  yourself  these  causes 
at  work — the  gradual  washing  away  of  land  by  the 
action  of  water,  the  crumbling  of  rock  by  the  action 
of  ice;  and  in  parts  of  the  world  new  islands  have 
been  thrown  up  by  volcanoes,  and  new  land  formed 
at  river-mouths.  These  you  may  not  see,  but  they 
are  going  on  now,  and  you  may  read  the  accounts 
written  by  people  who  have  seen  them. 

In  order  that  you  may  understand  geology,  I  am 


What  is  Geology?  7 

going  to  try  to  show  you  the  things  that  are  happen- 
ing now  by  means  of  the  same  forces  that  fashioned 
the  crust  of  the  earth,  for  a  great  distance  down,  in 
the  past.  The  forces  that  raised  up  our  continents 
out  of  the  depths  of  the  sea,  that  built  our  mountain- 
chains,  hollowed  out  the  beds  of  our  lakes,  ploughed 
the  channels  of  our  rivers,  and  built  up  layer  upon 
layer  our  solid  beds  of  rock,  and  then  Avore  them  down 
into  powdered  rock  or  earth  on  which  the  plants  and 
trees  can  grow  and  animal  creation  live — these  forces 
in  geologic  times  were  what  they  are  now,  stronger 
and  fiercer  in  the  new-born  earth,  perhaps,  but  the 
same.  And  as  we  go  along  studying  our  present 
earth  and  its  changes,  we  Avill  look  back  to  the  past, 
and  try  to  interpret  the  unknown  by  the  known. 


CHAPTER   II. 

THE  CLEW  FOUND   IN  THE  ROCKS. 

MORE  than  sixty  years  ago  there  lived  in  a  fishing 
town  on  the  north-eastern  coast  of  Scotland  a  boy 
who  afterwards  became  a  very  famous  man.  When 
he  was  only  five  years  old,  his  father,  who  was  a 
sailor,  was  lost  at  sea.  His  mother,  though  very  poor, 
managed  to  send  little  Hugh  to  school,  and  there  he 
learned  a  good  deal  from  books  ;  but  if  he  had  learned 
no  more  than  to  read  and  to  write,  he  would  proba- 
bly have  still  been  a  great  man,  for  in  the  mean  time 
he  had  found  something  else  worth  more  to  him  than 
many  books.  He  had  learned  to  read  another  lan- 
guage. He  had  found  out  that  he  had  two  eyes,  and 
how  to  use  them.  The  rocks  about  the  Firth  of  Cro- 
marty  were  waiting  for  just  such  a  pair  of  eyes  to 
read  their  open  secrets.  Thousands  of  boys  had 
played  about  those  rocks,  and  thousands  of  men  had 
fished  and  spread  their  nets  and  loitered  there,  but  no 


The  Clew  Found  in  the  Rocks.  9 

one  of  them  all  had  read  the  writing  on  the  stones  till 
Hugh  Miller  came. 

The  boy  used  to  go  down  to  the  beach  with  his 
uncle  Sandy  when  the  tide  was  low,  and  look  at 
the  ripples  left  in  the  sand  by  the  water.  He 
would  gather  shells,  half  buried  in  the  sand,  and  sea- 
weed lying  upon  it.  His  uncle  had  eyes  that  saw, 
too — it  seemed  to  run  in  the  family — and  he  helped 
little  Hugh  to  see  the  wonderful  life  of  the  sea-shore, 
and  to  think  about  what  he  saw.  These  lessons, 
far  more  than  anything  he  had  read  in  books,  helped 
him  in  after-life,  though  he  was  a  great  reader  of 
books  too. 

When  Hugh  grew  to  be  a  tall,  lanky  boy  he  chose 
his  work  in  life ;  he  chose  to  be  a  mason.  His  work 
lay  in  a  quarry  near  Cromarty,  close  by  his  beloved 
sea.  One  day,  as  the  men  were  lifting  up  the  great 
slabs  of  sandstone,  Hugh  saw  some  markings  on  the 
piece  of  rock  laid  bare.  These  were  the  old  familiar 
ripple-marks  in  the  solid  stone — just  such  marks  as 
he  had  often  seen  on  the  sandy  beach  (Fig.  1).  He 
did  not  say,  "How  strange!"  and  then  forget  all 
about  it.  He  began  to  think,  and  ask  himself  ques- 
tions. Could  it  be  that  this  was  an  old  sea-beach? 


10 


The  Earth  in  Past  Ages. 


How  could  it  be,  under  those  tons  and  tons  of  solid 
rock?  The  answer  came  to  his  questions  after  a 
while. 

Strewn  along  the  water's  edge,  washed  up  by  the 
waves,  were  curious  roundish  pieces  of  limestone  rock. 

One  day,  hammer  in 
hand,  Hugh  strolled 
along  the  beach.  He 
struck  one  of  these 
lumps,  and  it  broke 
open,  showing  embed- 
ded in  part  of  the  stone 
a  creamy -white  shell, 
beautifully  carved,  and 
showing  tints  of  color 
like  the  pearly  lining 
of  many  of  our  shells. 
Another  and  another 
of  these  stones  were 
broken  open  (Fig.  2).  In  some  of  them  he  found 
scales  of  fish ;  in  others,  fern-leaves  (Fig.  3) ;  in  others, 
again,  bits  of  decayed  wood — all  in  solid  stone. 

Now  he  could  answer  his  questions.     These  things 
had  once  been  alive.    He  had  spelled  out  one  word 


Fig.  1. — SLAB  OF  RIPPLE  -  MARKED  SAND 

STONE. 

From  Lyell's  "Elements  of  Geology." 


The  Clew  Found  in  the  Rocks*  11 


Fig.  2. — SHELL  IN  THE  ROCK  (Ammonite). 

from  the  tables  of  stone  written  upon  by  the  finger  of 
God  himself.  He  had  found  the  clew  in  the  rocks, 
and  he  never  rested  until  he  had  followed  up  this  clew, 
and  found,  by  examining  the  rocks  themselves,  and 
by  reading  about  what  other  men  had  discovered, 
how  the  earth  as  it  is  had  come  into  being. 


12 


The  Earth  in  Past  Ages. 


Fig.  3. — FERN-LEAF  IN  STONE. 


If  you  have  never  carefully  looked  at  the  rocks  of 
a  railway -cutting  as  your  car  went  through  it,  be  sure 
that  you  do  so  the  very  first  chance  that  you  have. 

You  will  probably  see  that 
the  rocks  are  in  layers. 
Sometimes  these  lie  level 
with  the  ground;  some- 
times they  are  very  much 
bent  or  tilted  (Fig.  4). 

To  understand  how  these 
came  to  be  so,  we  must 
understand  some  things 
which  are  very  simple,  but 

yet  they  are  things  that  we  would  not  naturally  think 
of.  What  we  call  earth,  or  soil,  is  only  rock  finely 
powdered,  mixed  up  with  some  of  the  dust  from  the 
dried  parts  of  dead  plants  and  animals.  Earth  is  to 
rock  about  what  the  pulverized  sugar  you  sprinkle 
over  your  berries  is  to  the  block-sugar  your  mother 
drops  into  your  tea. 

The  surface  of  the  earth  was  once  rock  which  had 
no  layers  in  it,  like  granite.  Part  of  the  round  globe 
was  covered  with  water,  and  a  little  of  it  was  dry 
land.  The  beating  of  this  old  ocean's  waves,  the  rain, 


The  Clew  Found  in  the  Rooks.  13 

the  air,  all  helped  to  grind  the  rock  to  powder,  and 
with  it  muddy  the  sea-water.  Take  a  tumbler  of  wa- 
ter, and  into  it  drop  a  teaspoonful  of  finely  ground 
earth.  Your  muddy  water  is  something  like  the  sea- 
water  was  then.  JSTow  watch,  and  you  will  see  what 


Fig.  4.— TILTED  LAYERS  IN  THE  ROCK. 

happened.  The  fine-powdered  rock  settled  in  the  bot- 
tom of  the  sea-bed  as  the  earth  settles  in  your  tum- 
bler, and  the  first  layer  Avas  made.  Layer  after  layer 
was  formed  in  this  way.  After  a  while  "  the  spirit 
of  God  moved  upon  the  face  of  the  waters."  A  fee- 
ble  life  stirred  in  the  bottom  of  the  sea.  Some  very 
simple  animals  lived  there,  and  we  can  find  the  curi- 


14  The  Earth  in  past  Ages. 

ous  shells  in  which  they  lived  in  those  deep -down 
rocks.  We  know  that  plants  must  have  come  first, 
because  plants  are  the  only  fairies  that  can  turn  rock 
and  earth  and  water  into  the  food  that  all  animals 
need  to  feed  upon ;  but  the  soft,  delicate  sea-weed  had 
died  and  left  no  sign.  The  early  animals,  however, 
had  hard,  glassy  shells,  and  when  they  died  these 
shells  sank  to  the  bottom  of  the  sea,  and  the  next 
layer  of  powdered  rock  settled  over  them  and  pre- 
served them — some  of  them  until  no\  . 

You  can  see  how  this  would  be,  and  that  when  we 
lay  open  the  rocks,  as  Hugh  Miller  did  with  his  ham- 
mer, we  might  find  the  shells.  Here  is  a  drawing  of 
a  bit  of  such  earth  that  was  turned  into  stone,  with 
its  corals  and  shell  lying  thick  in  the  layer,  which  is 
half  broken  away  (Fig.  5).  This  was  picked  up  just 
below  my  house,  on  the  shores  of  Newark  Bay. 

The  work  went  on  through  thousands  of  years,  the 
sea  laying  one  upon  another  these  wonderful  beds  of 
rock  of  different  kinds.  All  this  was  not  an  adding 
to  what  already  existed,  but  only  a  new  arrangement, 
with  some  change  in  the  character  of  the  old  materi- 
als already  there.  How  this  great  earth  came  to  be 
is  one  of  the  secret  things  of  God.  The  Bible  begins 


The  Clew  Found  in  the  Rocks.  15 

with,  "  In  the  beginning  God  created  the  heavens  and 
the  earth."  That  is  all  we  know.  A  guess  here  and 
there  has  been  made  as  to  how  it  was  done,  but  no 
one  knows,  and  no  one  probably  ever  will  know. 


Fig.  5.  —SHELLS  IN  BROKKN  ROCK. 

But  we  can  tell  the  way  the  crust  of  layers  was  put 
on,  because  we  can  watch  the  same  things  going  on 
now  which  went  on  thousands  and  thousands  of  years 


16  The  Earth  in  Past  Ages. 

ago.  At  the  bottoms  of  shallow  seas  and  lakes,  at  the 
mouths  of  rivers,  in  the  coral  islands  of  the  Pacific, 
the  earth  is  still  a-building. 

About  a  hundred  years  ago  men  began  to  be  inter- 
ested in  these  strange  things  found  in  the  stones. 
They  hunted  up  pieces  of  such  stone,  and  wrote  out 
all  they  could  find  about  it.  They  arranged  the  facts, 
and  called  the  new  science  geology,  or  the  science  of 
the  earth. 

It  is  very  easy  to  see  that  if  the  seas  had  stayed  all 
the  while  in  the  same  place,  with  no  disturbance  going 
on,  that  the  layers  would  have  settled  one  on  top  of 
the  other,  according  to  age,  the  oldest  being  the  low- 
est, and  so  on  up.  But  you  must  remember  that  the 
earth  was  then,  as  it  is  now,  part  dry  land  and  part 
water,  though  there  was  much  less  land  in  proportion 
then  than  there  is  now.  It  was  only  under  water  that 
the  layers  were  formed.  But  there  were  other  things 
at  work  besides  this  gentle  wearing  away  of  the  rocks 
and  building  up  of  the  sea-bottoms. 

Long  ago  people  believed  that  under  the  volcano  of 
^Etna,  on  the  island  of  Sicily,  a  giant  was  imprisoned, 
and  that  the  trembling  and  cracking  of  the  earth  be- 
fore an  eruption  were  his  struggles  to  get  free.  This 


The  Clew  Found  in  the  Rocks. 


17 


had  a  meaning  in  fact,  though  it  was  only  a  fable.  Un- 
der the  whole  earth  the  giant  fire  has  been  imprisoned. 
When  the  crust  of  the  earth  was  thinner  than  it  is 
now,  the  giant's  struggles  cracked  and  bent  it ;  some- 
times the  bottom  of  the  sea  would  be  suddenly  lifted 


„;,,     ;_        V  . 

Fig.  6. — LEVEL  AND  LIFTED  LAYERS. 

up,  and  the  dry  land  would  sink  and  be  covered  with 
the  waters  of  the  ocean  (Fig.  6).  On  the  left  side  of 
the  picture  are  the  level  layers  of  rock,  broken  up  so 
that  they  look  like  a  stone  wall.  After  a  while  we 
will  see  just  why  these  are  so  broken.  On  the  right- 
hand  side  you  see  the  layers  are  lifted  up  by  the  cu- 


18  The  Earth  in  Past  Ages. 

rious,  curly-looking  rock  which  boiled  up  out  of  the 
earth  beneath  as  lava  comes  out  of  a  volcano.  Which- 
ever part  of  the  earth  happened  to  be  under  the  water 
would  be  covered  up  with  layers  of  mud,  and  in  them 
plants  and  shells,  fish  and  animals,  would  be  buried, 
and  their  hard  parts  preserved.  The  other  part,  the 
dry  land,  would  not  be  very  much  changed  ;  the  plants 
and  animals  there  would  die,  and  mostly  be  blown 
away  as  dust. 

This  history  of  the  earth  written  upon  the  rocks, 
you  can  see,  is  not  a  very  easy  history  to  read.  Its 
leaves  were  all  scattered  and  torn  and  twisted,  and 
the  writing  on  them  often  rubbed  out,  and  many  of 
them  lost.  It  had  to  be  gone  over  again  and  again, 
in  many  different  places  and  by  many  different  men, 
before  these  stone  leaves  could  be  put  together  in  the 
right  order. 

If  these  layers,  or  strata,  as  they  are  called,  had  re- 
mained just  as  they  were  placed,  there  would  have 
been  no  way  to  reach  them  but  to  dig  down  to  them, 
for  twenty  miles  in  some  places,  and  that  would  have 
been  impossible :  nobody  has  ever  been  down,  in  the 
deepest  mine,  more  than  a  mile.  But  the  movements 
of  the  earth's  surface,  caused  by  the  struggling  fire 


The  Clew  Found  in  the  Rocks.  19 

underneath,  would  tilt  and  break  through  the  layers, 
and  so  the  broken  edges  would  be  on  the  surface  (Fig. 
6),  and  the  geologist  could  in  places  study  the  very 
bottom  layers  without  digging  down  to  them. 


CHAPTER  III 
WATER. 

Geology  has  nothing  to  tell  us  about  how  the  great 
mass  of  the  earth  was  first  created.  There  have 
been  many  guesses,  but  they  have  never  been  proved 
to  be  correct  ones.  What  we  hope  to  find  out  by 
studying  geology  is  how  the  surface  of  our  earth 
came  to  be  as  it  now  is,  with  its  seas  and  conti- 
nents, mountains  and  lakes,  rocky  peaks  and  sandy 
deserts.  This  was  the  work  of  the  same  forces  still 
busy  in  changing  the  face  of  the  earth  —  the  air 
above,  the  water  on  the  surface,  and  the  fires  under 
the  earth.  So  we  will  only  go  back  to  the  time  when 
the  earth  was  a  rocky  globe,  intensely  hot  inside,  and 
covered  with  a  universal  sea,  when  the  earth,  as  it 
moved  round  the  sun,  might  be  compared  to  a  mighty 
drop  of  dew  moving  round  a  globe  of  glowing  fire. 
We  must  get  rid  of  all  our  notions  of  the  world  as  it 
is  now  in  order  to  go  back  in  imagination  to  that 


Water.  21 

time.  The  earth  was  not  beautiful  then,  the  land  was 
not  adorned  with  trees  and  grass  and  lovely  flowers, 
the  air  was  not  full  of  humming  insects  or  swift-flying 
birds,  nor  the  waters  of  darting  fish  and  delicate  float- 
ing sea-weed.  It  was  a  desolate  waste  of  waters,  a 
shoreless  sea,  whose  tides,  instead  of  rising  and  falling 
and  breaking  upon  some  sandy  beach,  followed  the 
moon,  sweeping  unbrokenly  around  the  globe.  There 
were  no  blue  skies  overarching  the  wide  waters,  no 
fleecy  clouds  turning  to  gold  in  the  sunsets.  A  heavy 
mass  of  leaden  clouds  covered  the  sky,  a.nd  poured 
down  into  the  hot  seas  hot  rain-water  day  and  night. 

The  only  things  in  the  world  then  were  rocks  and 
water,  fire  and  air.  But  as  the  earth  cooled,  these 
forces,  the  moving  water,  the  fire  and  the  air,  went  to 
work  and  began  building  the  continents  and  islands, 
and  dividing  up  the  waters  into  seas  and  rivers  and 
lakes. 

First  came  the  fire  and  lifted  up  part  of  the  earth's 
crust  in  its  struggles ;  another  part  of  the  crust  would 
go  down,  and  into  these  low  valleys  the  waters  would 
collect,  leaving  the  high,  bare  rocks  standing  up  out 
of  the  sea.  In  this  same  way  many  islands  and  conti- 
nents arose  out  of  the  sea.  Next  came  the  turn  of  the 


22  The  Earth  in  Past  Ages. 

air  in  the  work  of  world-building.  The  air  around 
the  earth  then  was  like  the  air  now,  only  that  it  had 
a  great  deal  more  moisture  in  it,  and  the  gas  that 
comes  from  burning — called  carbonic  acid  gas — than 
our  air  has.  Such  air  as  this  has  a  very  peculiar  effect 
upon  some  sorts  of  rock :  it  slowly  dissolves  them  ; 
the  waves  of  the  sea,  or  the  rivers  pouring  over  the 
rocks,  soon  carry  this  dissolved  rock,  or  earth,  as  it 
really  is,  away,  and  finally  it  settles  in  the  ocean, 
forming  layers  of  soil,  which  after  a  while  become 
solid  rock  again.  Then  again  these  layers  are  uplift- 
ed, and  again  they  become  rotted  partly  away,  car- 
ried off,  and  deposited.  This  is  not  mere  guess-work. 
The  world  is  not  done  yet ;  it  is  still  a-making ;  just 
the  very  same  things  are  happening  now  in  various 
parts  of  the  world  as  went  on  of  old. 

Islands  have  suddenly  risen  out  of  the  sea,  and  men 
have  seen  them.  At  the  mouths  of  great  rivers  and 
in  the  bottoms  of  ponds  land  is  forming  all  the  while. 
In  some  places,  on  the  dry  land,  rock  where  it  stands 
is  rotted  into  earth,  and  gradually  washed  away  by 
the  rain;  and  where  the  weather  is  cold  enough  to 
freeze,  this  work  goes  on  faster  still.  When  you  have 
an  opportunity  to  examine  a  piece  of  brown  stone, 


Fig.  7. — STRATIFIED  ROCK  CLIFFS  AT  TROUGH. 


Water.  25 

used  so  much  to  build  houses  of,  or  as  facings  to  brick 
houses,  look  carefully  at  it.  You  will  be  apt  to  find 
that  there  are  on  the  surface  loose  flakes  which  you 
can  rub  away  with  your  finger.  Brown  stone  is  full 
of  little  cracks  and  crevices  and  openings — the  water 
soaks  into  these,  and  when  it  freezes  it  pries  off  the 
piece  of  stone  above  it;  the  ice,  taking  more  room 
than  the  water,  a,cts  as  a  wedge.  When  the  earth 
became  cool  enough  to  permit  the  rain  to  freeze,  the 
rocks  were  in  this  way  more  quickly  reduced  to  earth. 

Just  the  same  things  went  on  in  those  days  that  go 
on  now,  only  they  were  more  violent.  The  cool  crust 
of  the  earth  was  thinner ;  the  inner  fire,  therefore, 
oftener  succeeded  in  breaking  its  way  out ;  the  earth 
was  more  shaken ;  its  crust  was  more  torn  and  crum- 
pled. There  were,  of  course,  more  earthquakes,  a 
larger  number  of  volcanoes,  and  greater  quantities  of 
rain  fell  into  wider  seas. 

See  the  picture  of  the  Eocks  at  Brough.  These 
cliffs  have  been  slowly  deposited  in  layers,  and  then 
lifted  up  by  the  fire,  tilted  as  you  see,  as  they  were 
raised,  and  then  again  they  have  been  worn  away 
by  the  waters.  In  one  place  an  archway  has  been 
made  directly  through  them. 


26  The  Earth  in  Past  Ages. 

When  the  layered  rock  is  lifted  up,  it  is  of  course 
very  much  strained  and  cracked ;  the  water  gets  into 
these  cracks,  and  so  does  its  work  much  faster.  The 
Clett  (Fig.  8)  is  a  single  pillar  of  layered  rock  stand- 
ing up  in  the  sea.  The  layers  in  this  rock  correspond 
exactly  to  those  on  the  cliff  near  by,  showing  that  it 
was  once  part  of  a  great  cliff  reaching  out  into  the 
sea. 

Water  does  some  very  wonderful  things  when  it 
falls  over  a  precipice,  and  so  makes  a  cataract.  At 
Niagara  the  waters  of  the  great  lakes  on  their  way 
to  the  sea  fall  over  a  high  precipice  of  rock.  This 
precipice  is  made  of  very  hard  rock  on  the  top,  while 
the  layers  underneath  are  much  softer.  The  boiling 
of  the  waters,  after  tumbling  over  the  high  cliff,  grad- 
ually wears  away  the  softer  rock  below,  then  the 
upper  layers  stand  out  like  a  shelf,  and  over  this  the 
water  falls.  The  rush  and  strain  finally  crack  off  the 
projecting  shelf,  and  it  breaks  and  falls ;  then  again 
the  softer  rock  is  hollowed  out ;  another  shelf  forms 
and  is  broken  away.  In  this  way  the  water-fall  has 
worked  its  way  backward  for  seven  miles,  as  the  rocks 
on  each  side  of  Niagara  River  show. 

Great   rivers   like  the   Mississippi   wash   up   earth 


Water.  29 

where  they  flow  swiftly  from  high  land  to  low  land ; 
when  they  come  to  a  more  level  country  they  "  slow 
up,"  and  begin  to  drop  the  earth.  Anything  which 
makes  the  current  run  slower  causes  this  sort  of  a  de- 
posit. Where  two  currents  meet,  as  where  the  Ohio 
flows  into  the  Mississippi,  the  two  jostling  together 
hinder  each  other,  and  in  the  contest  earth  is  dropped, 
and  a  sand-bar  is  formed,  making  the  river  very  shal- 
low there.  No  matter  how  many  times  such  a  bar  is 
removed,  it  comes  again.  Where  the  Mississippi  emp- 
ties into  the  Gulf  the  current  spreads  out,  and  so  slows 
very  much,  and  a  great  deal  of  earth  is  dropped.  The 
jetties  made  by  Captain  Eads,  of  which  you  have 
probably  heard,  are  banks  built  into  the  Gulf  to  carry 
the  river  currents  swiftly  out  into  the  deep  water, 
and  there  allow  the  earth  to  be  dropped  where  it  will 
not  make  the  channel  too  shallow  for  ships  to  pass 
through  easily. 

Some  rivers  in  India  have  built  up  their  beds  by 
dropping  earth  in  this  way  all  along  through  the  low 
plains,  until  the  bottom  of  the  river's  bed  is  higher 
than  the  country  around.  When  the  river  overflows 
its  banks,  the  fields  beyond  the  high  bed  are  flooded. 
Then,  when  the  river  sinks  again,  the  water  cannot 


30  The  Earth  in  Past  Ages. 

get  back  into  the  channel,  and  it  lies  on  the  fields  and 
kills  the  crop. 

Certain  kinds  of  rocks  are  more  easily  dissolved  by 
water  and  carbonic  acid  than  others.  When  layers 
of  different  kinds  of  rock  are  exposed  to  the  air,  they 
crumble  away  very  unevenly,  and  so  make  curious- 
shaped  rocks,  sometimes  standing  up  like  monuments 
in  the  sea  or  on  land. 

In  rocks  which  are  not  dissolved  in  this  way  the 
water  sinks  into  the  cracks  and  flows  away,  doing 
very  little  work ;  but  in  limestone  rocks,  which  the 
water  does  dissolve,  the  crack  is  washed  larger  and 
larger,  till  a  cave  is  hollowed  out  in  the  solid  stone 
down  under  the  surface  of  the  ground.  The  water 
goes  on  trickling  and  dripping  from  the  roofs  of  these 
caves,  and  decorates  them  just  as  the  freezing  water 
in  winter  decorates  the  edge  of  your  portico  roof  with 
icicles.  I  am  sure  you  have  often  watched  icicles  form. 
As  the  rain  fell  from  the  roof,  drip,  drip,  drip,  each 
little  drop  left  a  little  bit  of  itself  behind  frozen,  and 
so  an  icicle  gradually  grew  from  these  many  drops. 

But  perhaps  you  were  too  busy  looking  at  the  sky 
to  see  if  it  were  going  to  clear,  to  notice  what  hap- 
pened underneath  the  icicle  on  the  portico  steps  or 


Fi£.  9. — "THE  CATHEDRAL,"  LURAY  CAVES,  VIRGINIA. 


Water.  33 

the  ground.  There  each  drop  left  a  little  of  itself 
again  before  running  away,  and  a  heap  of  ice  was 
formed.  Now,  in  the  limestone  caves  just  this  sort  of 
thing  happens.  The  water,  instead  of  leaving  a  little 
of  itself  frozen  behind,  leaves  a  little  of  the  limestone 
that  was  dissolved  in  it  behind,  and  great  stone  icicles 
are  formed,  which  never  melt.  These  are  called  sta- 
lactites, and  below  them  the  mounds  of  stone  grow 
up,  often  far  finer  than  the  stalactites.  The  stalactite 
from  above  and  the  heap,  or  stalagmite,  below  often 
meet,  and  so  form  a  pillar  from  floor  to  roof.  Some 
of  the  best  examples  of  these  formations  are  found  in 
the  Luray  Caves,  Virginia  (Fig.  9). 

These  limestone  caves  are  sometimes  so  near  the 
surface  of  the  ground  that  the  roof  gives  way,  broken 
in  by  the  roots  of  a  tree,  and  down  goes  the  living 
tree  into  a  great  hole  in  the  earth.  These  are  very 
common  in  the  limestone  section  of  Kentucky,  and  go 
by  the  name  of  sink-holes.  In  the  "Western  country 
some  of  the  rivers  rush  into  such  openings,  and  run 
underground  for  miles  through  cavern  after  cavern ; 
these  are  called  lost  rivers ;  but  far  away,  perhaps,  the 
same  river  comes  to  light  again,  though  it  is  not  always 
recognized  as  the  same. 
3 


CHAPTER   IV. 
THE  REIGX  OF  FIRE. 

You  remember  that  besides  the  water  and  the  air 
that  helped  to  fashion  our  beautiful  earth  out  of  the 
globe  of  rock  covered  by  a  heated  ocean  which  existed 
in  the  past,  another  force  has  been  mentioned — fire. 
Fire  is  still  working  day  and  night  in  changing  the 
world,  but  it  is  mostly  underground. 

Air  and  water  are  as  much  levellers  as  they  are 
builders.  If  only  these  two  forces  had  been  at  work, 
the  mountains  would  gradually  have  been  brought 
low,  and  the  valleys  exalted,  till  finally  every  rock 
and  island  would  have  been  worn  down  and  buried 
in  the  depths  of  the  sea.  The  world  would  have  re- 
turned to  the  condition  it  had  been  in  thousands  of 
years  before,  only  it  would  have  become  cooler. 

But  the  internal  fires  were  there  to  upset  all  this 
gradual  change.  They  were  never  at  rest.  Again 
and  again  the  sea-bottom  was  lifted  up  and  became 


The  Reign  of  Fire.  35 

dry  land,  and  the  Avaters  gathered  together  in  new 
hollows. 

Miners  who  go  down  into  the  earth  for  coal  and 
iron  find,  after  a  certain  distance,  that  it  grows  stead- 
ily warmer  and  warmer  as  they  descend.  If  the  heat 
of  the  earth  goes  on  increasing  at  this  rate,  at  thirty 
miles  below  the  surface  of  the  earth  the  heat  would 
be  so  intense  as  to  melt  even  iron  or  stone.  As  a 
matter  of  fact,  things  melt  a  great  deal  more  easily 
when  they  are  open  to  the  air  than  when  they  are 
under  pressure.  Down  deep  in  the  earth  the  pressure 
of  the  rocks  above  is  tremendous,  and  this  gets  heavier 
the  deeper  it  is.  So  there  is  a  battle  between  the  heat 
and  the  pressure  down  deep  in  the  earth,  and  whether 
the  rocks  there  are  melted  or  solid  depends  on  which 
is  the  stronger.  Some  people  think  that  all  but  a  thin 
shell  over  the  outside  of  the  world  is  red-hot  liquid ; 
others  think  it  is  hot  enough  to  be  liquid,  but  that  the 
pressure  keeps  it  solid.  However  this  may  be,  when- 
ever, from  any  cause,  the  pressure  is  sufficiently  light- 
ened, the  melted  stone  and  cinders  and  steam  come 
rushing  out.  Volcanoes  are  the  chimneys  by  which 
they  escape. 

The  cool  crust  of  the  earth  is  a  great  deal  thinner 


36  The  Earth  in  Past  Ages. 

in  proportion  to  the  rest  of  the  globe  than  an  egg- 
shell is  to  the  egg.  In  old  geologic  times  the  shell 
was  thinner  even  than  it  is  now.  The  fires  then  work- 
ed wonderful  changes,  the  same  in  kind  as  they  are 
working  now,  but  much  greater.  The  earth's  crust- 
made  of  many  layers  of  different  kinds  deposited  by 
the  water — was  crumpled  and  torn  and  twisted  in  a 
most  remarkable  way. 

The  struggles  of  the  internal  fires  often  produce  a 
sound  and  shaking  —  an  earthquake.  Suppose  you 
were  to  lower  a  can  of  gunpowder  (sealed  up  tight, 
and  so  arranged  that  it  would  go  off  in  half  an  hour) 
into  a  pond.  When  the  powder  took  fire  it  would 
explode,  and  as  soon  as  the  commotion  reached  the 
top  of  the  water  a  wave  would  spread  out  from  the 
point  above  the  explosion.  An  earthquake  is  such  an 
explosion,  only  it  is  underground ;  the  earth  is  thrown 
into  waves,  but  instead  of  rocking  and  moving  off  as 
the  water  does,  the  ground,  being  solid,  is  torn  and 
broken,  and  if  the  shock  is  severe,  houses  are  thrown 
down  and  people  destroyed.  Sometimes  things  are 
thrown  straight  up  into  the  air  by  an  earthquake 
shock;  at  other  times  they  are  shaken  backward  and 
forward  till  they  fall  in  ruins.  The  movement  of  the 


The  Rdgn  of  Fire. 


37 


earth  during  a  shock  is  at  times  a  curious,  twisting 
motion,  which  has  been  known  to  turn  pieces  of  fur- 
niture around  so  that  their  faces  were  to  the  wall. 
Rows  of  trees  have  been  found  all  twisted  out  of  line, 
though  still  growing,  after  such  a  shock.  We  are  apt 
to  think  of  earthquakes  as  being  very  rare,  and  so 
they  are  with  us;  but  in  hot  countries  they  are  so 
common  that  it  is  probable 
that  some  part  of  the  earth  is 
quaking  all  the  time. 

Sometimes,  when  the  shock 
is  not  very  severe,  the  earth 
cracks  underneath,  but  the 
cracks  do  not  quite  come 
through.  The  melted  stone 
then  pours  up  and  fills  the 
cracks  (Fig.  10),  and  hardens 
there.  The  intense  heat  of 

the  melted  stone  often  changes  the  rock  through 
which  it  flows.  Limestone,  which  is  a  rather  soft 
stone  made  up  largely  of  shells,  is  turned  into  mar- 
ble in  this  way.  Marble,  then,  is  merely  "cooked" 
limestone. 

In  Fig.  11  you  see  a  cut  through  a  part  of  the  earth's 


Fig.  10.— ROCK  VEINS. 

From  Hooker's  "  Mineralogy 
and  Geology." 


38  The  Earth  in  Past  Ages. 

surface.  At  first,  underneath  all,  was  the  melted 
stone  ;  over  this  formed  the  layered  rocks.  Then  the 
melted  stone  rose  up,  lifting  the  layers  S  S  as  it  rose. 


$     3       C      J>     E 
Fig.  11. — SECTION  OF  THE  EARTH'S  CRUST. 

As  time  went  on,  the  air  and  water  washed  the  layers 
from  the  top  of  the  mountain,  leaving  it  bare  (A). 
After  a  while  an  earthquake  cracked  the  earth,  and 
more  melted  rock  poured  up.  At  B  the  cracks  only 
reached  part  of  the  way  up,  and  the  lava,  after  rising 
to  the  top  of  the  crack,  spread  out  between  two  layers. 
At  C  it  reached  the  top  and  flowed  over  the  ground, 
making  a  solid  slab  of  volcanic  rock  on  top  of  the 
layered  rock.  At  E  the  lava  came  out  with  such  a 
rush  that  it  built  up  a  little  volcano  there. 

Yery  often,  when  one  stone  is  melted  in  this  way, 
the  crystals  of  another  kind  of  mineral  are  enclosed 


The  Reign  of  Fire. 


39 


in  it  (Fig.  12).  Here  is  another  curious  stone  made 
by  the  fire.  The  lava  cooled  full  of  bubbles,  and  with 
these  holes  another  mineral  collected  and  hardened, 
as  plaster  of  Paris  fills  a  mould  into  which  it  is  poured. 


FELDSPAR. 
From  Lyell's  "Geology." 


Fig.  13. — SCORIACEOUS  LAVA. 
From  Lyell's  "Geology." 


The  moulds  were  made  by  fire,  though  it  was  a  dis- 
solved and  not  a  melted  mineral  which  filled  them 
(Fig.  13). 

A  volcano,  you  know,  is  a  mountain  that  sends  out 
burning  gases  and  lava  and  cinders.  It  is  usually  a 
high  peak  with  a  cup-like  depression  in  the  top,  called 
a  crater.  The  volcanoes  of  the  world  are  found  al- 


40 


The  Earth  in  Past  Ages. 


most  always  near  the  sea,  and  nearly  three-quarters 
of  them  are  situated  upon  islands. 

If  you  have  a  globe — or  if  you  have  not,  a  map  of 
the  world — put  your  finger  on  Terra  del  Fuego  (the* 
land  of  fire),  at  the  very  southern  part  of  South  Amer- 
ica, then  run  it  along  the  western  coast  of  the  two 
continents — the  Andes  and  the  Rocky  Mountains  being 
your  guide — till  you  get  to  Alaska,  where  Asia  and 
America  almost  touch ;  pass  over  to  the  Aleutian  Isl- 
ands and  down  by  way  of  islands  across  the  Indian 
and  Pacific  oceans  back  to  Terra  del  Fuego  again. 


Fig.  14. 


Fig.  15. 


GRAPHIC  GRANITE. 


Fig.  14.— Section  parallel 
to  the  laminae. 


Fig.  15. — Section  transverse  to  the 
laminae. 


Your  finger  will  have  passed  over  most  of  the  large 
volcanoes  in  the  world.  It  is  'as  if  the  earth's  crust 
were  cracked  all  around  in  this  irregular  line,  that  the 


The  Reign  of  Fire.  41 

mountain-chains  Avere  the  raised  edges  of  this  crack, 
and  that  the  crack  gave  way  every  now  and  then, 
and  through  the  broken  places  melted  stone  and  gas 
and  flames  rushed  out. 

Some  of  the  grandest  volcanoes  in  the  world  .are  in 
the  Pacific  islands.  One  of  the  Sandwich  Islands  is 
nothing  but  an  immense  volcano  with  three  craters. 
The  island  has  been  built  up  by  the  outpouring  of 
lava,  which  gradually  lifted  it,  craters  and  all,  out  of 
the  sea.  One  of  these  craters,  Mount  Kilauea,  is  an 
immense  wide  pit,  large  enough  to  hold  a  city.  The 
rocky  plain  at  the  bottom  of  the  pit,  when  there  is  an 
eruption,  breaks  up  and  fills  with  lava.  It  is  a  won- 
derful sight  to  see  these  great  lakes  of  red-hot  melted 
stone  boiling  and  bubbling  like  a  great  pot  of  boiling 
water,  and  the  red-hot  waves  beating  against  the  rocky 
shore,  and  spurting  fountains  of  fire  rising  up  here 
and  there.  In  one  eruption  the  weight  of  the  lava 
was  so  great  that  it  broke  through  the  side  of  the 
crater,  and  ran  down  a  river  of  living  fire  to  the  sea. 
When  it  met  the  water,  great  clouds  of  hissing  steam 
spouted  up,  carrying  the  cooled  and  shattered  lava 
with  it. 

The  lava  in  Kilauea  is  often  like  clear  glass,  and 


42  The  Earth  in  Past  Ages. 

when  the  bubbles  burst  in  the  boiling  lake  it  is  drawn 
out  into  fine  spun  glass,  which  the  wind  collects  in 
sheltered  spots.  The  Sandwich  Islanders  used  to  call 
it  Pele's  hair,  because  they  believed  their  goddess  Pele 
lived  under  the  crater,  and  caused  its  eruptions.  After 
I  wrote  these  words  a  curious  thing  happened  to  Ki- 
lauea :  the  bottom  tumbled  out  of  the  crater,  and  the 
boiling,  fiery  lakes  and  fountains  suddenly  sunk  in, 
and  left  it  a  great  dark  abyss. 

In  the  sea  near  the  coast  of  Greece,  more  than  two 
thousand  years  ago,  the  crater  of  a  great  volcano  was 
lifted  out  of  the  water.  It  made  a  sort  of  horseshoe 
island,  part  of  the  rim  having  been  broken  away. 
This  island  is  called  Santorin.  In  the  curve  of  the 
bay  enclosed  by  the  horseshoe  several  volcanoes  have 
burst  up  since,  and  are  still  sending  out  steam  and 
vapor.  The  water  around  them  is  hot,  and  is  colored 
orange  by  the  iron  and  other  things  thrown  out  by 
the  volcanoes. 

The  volcanoes  in  Europe,  such  as  ^Etna  and  Vesu- 
vius, are  different  from  Kilauea.  Before  an  eruption 
loud  noises  are  heard,  an  earthquake  shakes  the 
ground,  and  then  comes  a  sudden  outpouring  of  lava 
and  cinders  and  smoke.  In  one  of  these  eruptions, 


The  Reign  of  Fire.  45 

soon  after  the  time  of  Christ,  two  cities  were  buried 
by  an  overflow,  one  of  mud  and  the  other  of  cinders. 
A  little  more  than  a  hundred  years  ago,  in  digging  a 
well  in  a  town  that  had  grown  up  over  the  old  one, 
the  city  was  discovered.  Imagine  what  a  wonderful 
thing  it  must  have  been  to  walk  those  deserted  streets, 
sealed  up  for  nearly  two  thousand  years,  and  find  the 
houses,  the  baths,  the  libraries,  almost  uninjured ! 
These  buried  cities,  Herculaneum  and  Pompeii,  were 
destroyed — as  was  thought  until  their  rediscovery, 
about  the  middle  of  the  eighteenth  century — in  the 
year  79.  Some  day  you  will  read  about  them  in  Bul- 
wer-Lytton's  fascinating  romance,  "The  Last  Days 
of  Pompeii." 

In  Mexico,  in  a  peaceful  district  where  there  were 
fine  cotton  plantations,  a  hundred  and  thirty  years 
ago  lived  a  rich  planter  quietly  cultivating  his  crops. 
Suddenly  one  day  loud  and  terrible  noises  were  heard 
underground ;  earthquake  shocks  were  felt.  This  went 
on  for  two  months,  and  then  all  quieted  down.  After 
a  few  weeks  of  quiet,  the  noises  began  again,  the 
ground  for  about  four  miles  swelled  up  in  a  great 
bladder  five  hundred  feet  high,  which  rose  and  fell, 
till  finally  a  yawning  gulf  opened.  Two  rivers,  which 


4:6  The  Earth  in  Past  Ages. 

before  had  flowed  peacefully  through  the  country, 
plunged  into  this  opening  and  were  lost.  Thousands 
of  little  mud  volcanoes  burst  up  all  over  the  plain,  an 
immense  crater  opened,  and  poured  out  such  quanti- 
ties of  red-hot  stones  and  ashes  that  it  built  up  a  range 
of  six  mountains.  One  of  these  is  a  volcano,  called 
Jorullo,  which  has  been  active  ever  since. 


CHAPTER  V. 

FIRE  AND    WATER. 

THE  sea  along  the  western  coast  of  Scotland  is  filled 
with  numberless  islands,  which  look  on  the  map  as  if 
they  might  have  been  broken  from  the  solid  land. 
One  of  these  is  a  tiny  island  lying  close  in  the  em- 
brace of  a  larger  one.  Though  it  shows  as  a  mere 
speck  on  the  map,  this  little  island  of  Staffa  is  known 
the  world  over  for  its  wonderful  natural  formations. 
On.  the  edge  of  the  sea,  rising  direct  from  the  water, 
is  the  well-known  Fingal's  Cave  (Fig.  IT).  The  regu- 
larity of  its  formation  is  so  remarkable  that  it  is  hard 
to  believe  it  to  be  a  work  of  nature.  Lofty  columns 
of  regular  shape  stand  up  out  of  the  sea,  built  up,  it 
would  seem,  of  block  upon  block  of  solid  stone  care- 
fully chiselled  and  as  carefully  laid  upon  one  an- 
other. 

On  the  northern  coast  of  Ireland,  at  the  point  which 
is  nearest  the  Scottish  coast,  is  another  wonderful  as- 


48  The  Earth  in  Past  Ages. 

semblage  of  these  columns,  roofless,  and  running  oat 
into  the  sea,  called  the  Giant's  Causeway. 

An  old  story  makes  these  two  wonders  the  ruins  of 
castles  built  and  inhabited  by  two  unfriendly  giants. 


Fig.  17. — FINGAL'S  CAVE. 

The  cave  has  received  the  name  of  the  Scotch  giant, 
FingaL  There  are  many  old  poems,  sung  among  the 
Highlanders  in  the  far  past,  of  which  Fingal  is  the 
hero ;  but  we  now  know  that  no  man's  or  giant's  hand 
helped  to  lift  these  great  blocks  of  stone  one  upon  the 
other.  They  were  built  up  by  the  fires  under  the 
earth.  The  melted  stone  poured  out  of  the  volcanoes 
above  and  spread  over  the  land,  and  there,  as  it  hard- 
ened and  cooled,  split  up  into  great  crystals,  or  col- 
umns. The  water  dashing  for  thousands  of  years 


Fire  and  Water.  49 

against  them  washed  away  the  earth  around  and  the 
broken  fragments,  but  was  dashed  back  again  by  a 
few  of  the  hard,  unbroken  columns,  and  so  were  left 
Fingal's  Cave,  the  Giant's  Causeway,  and  other  forma- 
tions like  these. 

Too  long  ago  for  you  even  to  imagine  it,  there  was 
a  great  bridge  of  these  columns  reaching  from  Scot- 
land to  Ireland  ;  the  Giant's  Causeway  was  one  abut- 
ment, and  Fingal's  Cave  another.  In  the  thousands 
of  years  that  have  passed  since,  the  rest  of  the  bridge 
has  been  swept  away  and  destroyed,  with  only  here 
and  there  an  island  of  columns  between  to  tell  the 
tale. 

These  rocks — hardened  volcanic  rock — are  called 
basalt.  They  are  not  the  only  things  which  in  dry- 
ing contract  and  split  into  crystals.  Take  some  com- 
mon starch,  dissolve  it  in  water,  and  let  it  gradually 
dry.  When  it  is  perfectly  dry,  you  will  see  that  the 
sheet  is  full  of  quantities  of  fine  cracks  ;  loosen  it  from 
the  plate,  and  you  will  find  it  all  in  crystals.  Sulphur 
or  salt  will  crystallize  in  the  same  way.  Few  things, 
however,  split  up  as  regularly  as  basalt  does. 

Sometimes  where  there  has  been  a  wide  crack  in  the 
older  rocks  the  melted  basalt  has  run  into  and  filled 
4 


50  The  Earth  in  Past  Ages. 

the  crack.  In  that  case  the  stone  as  it  hardened  split 
up  the  other  way,  and  instead  of  columns  it  looks  like 
piles  of  logs.  On  the  coast  of  Lake  Superior  there  is 
a  remarkable  instance  of  this ;  the  surrounding  rock 
has  Avorn  away,  leaving  the  hard  basalt  lying  like  a 
carefully  arranged  pile  of  cord-wood. 

The  great  central  fires  of  the  earth  are  constantly 
at  work,  sometimes  acting  with  shocks,  and  some- 
times quietly  and  steadily  changing  the  face  of  the 
earth.  In  India,  seventy  years  ago,  one  of  these  sud- 
den changes  took  place  which  was  very  remarkable. 
There  was  an  earthquake  shock,  and  a  great  piece  of 
land  fifty  miles  long  and  sixteen  broad  was  suddenly 
lifted  up  ten  feet  higher  than  the  country  around, 
and  there  it  has  stayed,  with  a  straight  wall  around 
the  edge  called  by  the  natives  "  TJllah  Bund,"  or 
"  God's  Wall,"  from  the  mysterious  way  in  which  it 
arose. 

Without  any  earthquake  shock  or  sudden  move- 
ment continents  are  in  some  places  slowly  sinking 
and  in  others  as  slowly  rising.  It  might  seem  as  if 
it  were  the  waters  which  were  rising  or  falling,  but 
a  moment's  thinking  will  show  you  that  this  cannot 
be  so.  Water  soon  comes  to  a  level ;  and  as  there  is 


FIG.  18. — TEMPLE  OF  SERAPIS. 


OF    THE 

UNIVERSITY 

OF 


Fire  mid  Water.  53 

nearly  the  same  quantity  in  the  oceans  all  the  while, 
it  must  be  the  land  that  is  changing. 

There  was,  a  great  many  years  ago,  before  Christ 
came  into  the  world,  a  temple  built  on  the  Gulf  of 
Baiae,  near  Naples  (Fig.  18).  Three  pillars  of  this  tem- 
ple are  still  standing,  though  they  have  seen  many  ups 
and  downs  since  their  building.  The  original  pavement 
was  of  beautiful  mosaic,  and  so  well  built  that  it  still 
remains,  though  the  earth  on  which  it  stands  slowly 
sank  for  many  years.  About  two  hundred  years  after 
Christ  a  new  floor  was  laid  six  feet  above  the  old  one, 
showing  at  that  time  how  much  the  earth  had  sunk. 
Down,  down  the  pillars  went  into  the  sea,  till  they 
had  sunk  twenty-six  feet.  Then  came  a  terrible  erup- 
tion of  volcanic  lava,  and  the  temple  was  lifted  bodily 
more  than  twenty  feet,  the  pillars  still  standing  up- 
right. Twenty-six  feet  above  the  first  pavement,  and 
for  twelve  feet  below  that  line,  the  pillars  have  been 
fairly  pitted  by  some  small  sea-animal  which  had  bur- 
rowed into  the  marble  when  it  was  under  the  sea. 
The  story  of  the  temple's  travels  is  written  on  the 
face  of  the  pillars.  Now  the  temple  is  again  slowly 
sinking  at  the  rate  of  an  inch  a  year. 

Our  own  continent  is  tilting  up  in  some  places  and 


54  The  Earth  in  Past  Ages. 

sinking  down  in  others.  The  Florida  coast  is  sinking, 
the  North  Carolina  coast  is  rising.  Near  Boston  the 
land  is  rising,  and  Greenland,  for  six  hundred  miles,  is 
sinking  so  manifestly  that  the  Greenlanders  have 
learned  not  to  build  their  huts  close  by  the  sea.  An 
island  in  the  Gulf  of  St.  Lawrence  is  gradually  tip- 
ping; its  southern  coast  is  dipping  down  and  its 
northern  rising  into  high  bluffs. 

The  water  and  the  fire  in  doing  these  mighty  works, 
in  gradually  turning  and  tilting  continents  and  islands, 
and  wearing  them  down  again,  do  not  forget  some 
smaller  duties  in  the  way  of  carving  and  ornamenting 
and  beautifying  the  earth. 

There  is  no  country  in  the  world  which  has  more 
wonderful  hot  springs  than  our  own.  The  hot  water, 
filled  with  carbonic  acid,  which  comes  from  the  fires 
beneath  the  earth,  has  the  power  to  dissolve  certain 
minerals ;  these  it  brings  up  to  the  surface  of  the 
earth.  The  carbonic  acid  goes  off  in  gas  when  it 
comes  to  the  air,  but  the  lime  and  other  minerals  are 
allowed  to  settle ;  there  they  harden  and  form  a  cup, 
from  which  the  water  drips  down,  forming  limestone 
icicles  or  stalactites.  Finally,  cup  after  cup  is  formed 
in  this  way  (Fig.  19),  most  wonderfully  ornamented 


Fire  and  Water. 


55 


In  one  place  in  Italy  such  a  spring,  which  is  at  the 
top  of  a  hill,  has  encased  the  whole  hill  in  a  layer  of 
stone  formed  from  its  settlings. 
In    carbonated    springs    like 
those  in  Figure  19  most  of  the 
lime   settles  at  the   bottom,  as 
earth  will  in  water;   but  there 
is  a  still  more  wonderful  kind 
of  spring,  which  builds  its  own 
basin,  and  after  a  while  makes 
itself  into  a  fountain.     Such  a 
spring  is  called  a 
geyser.       These 
are  very  rare,  be- 
cause   it    takes 
so  many  different 
things  acting  to- 
gether  to   form 

them.       They   are  Fig.  19.— CARBONATED  SPRINGS. 

the    children     of 

fire  and  water.  Geysers  are  found  in  Iceland,  New 
Zealand,  and  our  own  Western  country  (Fig.  20). 
Those  in  the  Yellowstone  National  Park,  in  Wyoming 
Territory,  are  perhaps  the  largest  and  most  curious  in 


56  The  Earth  in  Past  Ages. 

the  world.  Indeed,  that  region  abounds  with  wonder- 
ful examples  of  Nature's  handiwork,  which  must  be 
interesting  to  all  students  of  geology. 

A  geyser  begins  by  being  a  little  hot  spring ;  it  ends 
by  being  a  natural  fountain.  Geyser  water  has  been 
put  into  a  basin,  and  allowed  slowly  to  dry  up.  It  is 
then  found  that  the  settlings  from  this  water  are  not 
on  the  bottom,  but  that,  as  the  water  dried,  it  ]eft  a 
solid  rim  around  the  basin,  and  as  it  sank  the  rim 
broadened  downward. 

In  the  geyser  water  there  is  a  white  and  glassy  sub- 
stance that,  as  it  settles,  builds  a  cup  for  itself ;  when 
the  water  overflows  the  cup,  it  naturally  runs  out  of 
the  lowest  place.  Here  the  solid  rim  is  built  up  by 
the  glassy  silica  till  that  gets  higher ;  the  water  then 
shifts  and  flows  over  the  lowest  place  left,  building 
slowly  the  lowest  places  in  the  rim,  till,  instead  of  a 
cup,  it  makes  a  high  tube  with  a  mound  of  silica  all 
around  it. 

Sometimes  the  water  will  lie  quiet  in  the  tube  for  a 
good  while  ;  but  the  fires  beneath  are  turning  water 
into  steam,  and  when  enough  steam  forms  it  lifts  the 
water  in  the  tube,  in  its  struggles  to  get  out,  until 
finally  the  water  is  thrown  up  into  the  air  violently, 


FIG.  20. — A  GEYSER. 


Fire  and  Water.  50 

like  the  jet  of  a  mighty  fountain.  The  steam  escapes 
in  a  single  burst  or  in  several;  the  water  sinks  back 
and  lies  quiet  for  a  while,  till  steam  is  again  formed, 
and  the  fountain  jets  again. 

A  toy  geyser  can  be  made  of  an  upright  tube  of  iron 
filled  with  water,  and  two  gas-jets  burning  against  the 
tube,  one  above  another.  Every  different  way  that  a 
geyser  plays  can  be  imitated  on  this  simple  little  ar- 
rangement. It  would  take  too  long  to  explain  why 
some  geysers  are  too  young  to  play  and  why  some  are 
too  old  ;  why  some  play  at  fixed  times,  and  otfhers 
only  when  a  clod  of  earth  or  something  of  the  kind 
is  thrown  into  the  tube ;  but  if  you  could  see  the  ex- 
periment tried  on  the  toy  geyser  it  would  not  be  hard 
to  understand. 


CHAPTER  VI. 
THE  ICE-KING  AT  WORK. 

WE  have  seen  how  water  wears  away  the  land  in 
one  place  to  build  it  up  in  another,  how  it  carves  chan- 
nels for  itself  through  the  solid  rock,  and  builds  up 
new  layers  of  rock  out  of  the  ground-up  material,  but 
we  have  not  seen  all  that  water  can  do.  In  its  solid 
form,  as  ice,  it  has  had  a  great  part  to  perform  in  world- 
making. 

I  am  sure  you  have  often  read  of  the  wonderful  gla- 
ciers of  Switzerland,  where,  between  the  rocky  sides 
of  a  mountain  gorge,  the  ice  seems  like  a  great  river 
flowing  downward.  Glaciers  are  found  in  many  coun- 
tries— everywhere,  in  fact,  where  the  climate  and  the 
formation  of  the  land  are  both  favorable.  We  hear 
more*  of  Swiss  glaciers  only  because  a  larger  num- 
ber of  people  visit  and  write  about  Switzerland  than 
about  the  other  countries  where  they  are  to  be  found. 
Greenland  and  Alaska  have  many  glaciers  quite  as 
wonderful  as  those  of  Switzerland. 


FIG.  21. — A  GLACIER. 


The  Ice-king  at  Work.  63 

A  glacier  is  really  what  it  looks  like — a  river  of  ice  ; 
and  more  than  that,  it  is  a  moving  river.  It  does 
not  seem  possible  that  anything  as  solid  and  as  brit- 
tle as  ice  could  move  in  this  way  through  an  uneven 
rough  channel,  and  fill  it  as  a  glacier  does. 

The  beginning  or  source  of  the  glacier  is  snow 
packed  tightly  in  a  high  mountain  valley.  As  we 
follow  its  course  it  gradually  changes  into  a  solid 
mass  of  whitish  ice,  scored  all  over  with  cracks  and 
crevices,  broken  up  into  great  masses  and  blocks  of 
ice  on  the  surface,  and  covered  often  with  dirt  and 
stones.  Finally  we  come  to  a  place  where  the  weath- 
er is  warm  enough  to  melt  the  ice,  and  then  it  flows 
off  as  a  stream  of  water. 

The  glaciers  had  been  for  a  long  time  under  suspi- 
cion of  moving,  but  it  was  not  generally  believed  till 
a  man  named  Hugi,  in  1827,  built  a  hut  upon  one  of 
them.  Each  year  it  was  found  that  the  hut  was  far- 
ther down  the  gorge. 

The  fact  was  proved,  and  people  became  interested 
in  finding  out  more  about  this  movement.  A  row  of 
stakes  was  set  up  in  the  ice,  straight  across  from  side 
to  side  of  the  glacier,  and  two  on  each  bank  to  mark 
the  starting-point.  This  row  of  poles,  as  it  moved,  did 


64  The  Earth  in  Past  Ages. 

not  remain  straight ;  it  bent  like  a  bow  in  the  middle, 
curving  out  towards  the  lower  end  of  the  glacier,  show- 
ing that  the  middle  part  moved  faster  than  the  edge. 
This  is  known  to  be  true  of  an  ordinary  river :  the 
water  rubbing  against  the  banks  and  against  the  bot- 
tom of  its  bed  is  hindered,  and  moves  more  slowly 
than  the  water  in  the  middle  and  on  top  does. 

The  glacier  ice  not  only  moves  where  the  channel 
is  even  and  smooth,  but  in  some  places  where  the 
channel  narrows  and  is  bordered  by  great  masses  of 
rock  the  wide  sheet  of  ice  squeezes  itself  through  the 
narrow  gorge,  piling  itself  high  in  mighty  blocks  in 
obedience  to  the  tremendous  pressure  behind.  Of 
course  most  of  this  movement  is  in  summer ;  the  ad- 
vance of  the  rows  of  stakes  showed  this.  There  are 
two  very  wonderful  things  to  be  studied  out  about 
this — the  cause  of  the  movement,  and  the  way  it  is 
effected. 

First  for  the  cause :  that  has  to  be  sought  in  the 
high  and  lonely  mountain  valleys.  Each  winter  snow 
piles  itself  high  on  the  mountain-top ;  each  summer 
this  snow  is  softened  and  made  slushy,  but  not  melt- 
ed entirely.  The  soft  snow  sinks  and  packs,  and  is 
pushed  down  into  the  easiest  channel.  The  next 


The  Ice-king  at  Work.  65 

winter  a  new  weight  of  snow  is  added,  making  a 
greater  pushing  force. 

On  a  cold,  clear  winter's  day  you  have  often  picked 
up  a  handful  of  snow  and  tried  to  make  it  into  a  snow- 
ball, and  found  that  it  would  not  pack ;  it  would  crum- 
ble up  in  your  hands.  By  putting  a  little  water  on  it 
you  can  pack  it  into  a  hard,  partly  clear  ball. 

If  moist  snow  is  put  in  a  mould  and  squeezed,  a 
block  of  ice  the  shape  of  the  mould  can  be  made. 
Your  hands  cannot  press  the  snow  hard  enough  to 
make  it  into  ice,  but  the  mould  can.  Snow  is  nothing 
but  ice  in  fine,  beautiful  crystals  with  air  caught  in  its 
meshes.  When  you  squeeze  it  you  press  out  the  air, 
and  bring  the  ice  particles  near  enough  together  for 
them  to  freeze  solid.  A  tiny  little  bit  of  water  added 
runs  in  between  the  particles  of  ice  and  pushes  the  air 
out  before  it,  and  so  helps  to  make  it  solid ;  and  when 
the  water  too  is  squeezed  out,  makes  it  freeze.  Too 
much  is  worse  than  none  at  all.  Each  winter's  weight 
of  snow  lies  during  the  cold  weather  without  doing 
much,  but  when  the  summer  warmth  begins  to  soften 
the  snow  it  begins  to  pack,  as  the  moist  snowball 
does,  and  being  a  little  softened,  and  pressed  by  the 
weight  above,  to  push  its  way  down  through  some 
5 


66  The  Earth  in  Past  Ages. 

valley.  It  is  hindered  in  its  travels,  and  being  pushed 
behind  and  hindered  in  front,  it  packs  tighter  and 
tighter  till  we  find  it,  farther  down  in  its  bed,  a  mass 
of  ice.  The  weight  is  getting  greater  and  greater  be- 
hind it  with  each  winter's  load  of  snow,  and  so  the 
ice  is  forced  down,  no  matter  what  is  in  the  way,  and 
the  valley  is  finally  filled  with  the  moving  river  of  ice. 
The  ice  is  not  soft  like  water,  or  even  mud ;  how, 
then,  can  it  fit  itself  to  the  channel?  That  has  puz- 
zled a  great  many  wise  heads  before  yours.  Ice  is  one 
of  the  brittlest  things  in  the  world,  but  it  has  a  quali- 
ty that  we  do  not  often  have  occasion  to  notice.  It 
melts  easily,  but  it  also  freezes  easily.  Faraday,  one 
of  the  greatest  men  of  science  in  our  century,  and  one 
of  the  noblest  and  simplest  men  of  any  time,  discov- 
ered this  quality  of  ice  in  a  very  commonplace  way. 
One  hot  summer's  day,  in  a  restaurant,  he  noticed 
some  bits  of  ice  floating  in  a  dish  of  water.  The  ice 
was  melting,  and  yet  every  time  two  pieces  touched 
they  froze  together.  Tyndall,  another  great  scientist, 
has  explained  the  movement  of  glaciers  by  this  simple 
principle.  It  was  he  who  found  that  ice  could  be 
crushed  out  of  one  shape  into  another,  and  that  the 
broken  bits  froze  at  once  together  and  made  a  solid 


The  Ice-king  at  Work.  67 

lump,  as  the  snow  does.  Now,  glacier  ice,  underneath 
the  surface,  is  squeezed  in  a  mould  made  of  its  bed  and 
banks  and  the  heavy  weight  of  ice  above ;  the  moving 
part  of  the  ice,  which  tits  itself  to  the  channel  mould, 
is  broken  and  ground  up  into  bits ;  but  these  bits,  being 
pressed  together  again,  freeze  into  the  new  mould  that 
it  is  pushed  into — that  is,  the  new  part  of  the  channel 
—just  as  Tyndall's  ice,  which  was  iirst  squeezed  in  a 
round  mould,  came  out  a  ball,  and,  being  squeezed 
again  in  a  cup-shaped  mould,  came  out  a  perfect  cup 
of  ice. 

A  glacier  moves  so  slowly  that  it  freezes  to  frag- 
ments of  stone  in  its  bed  and  on  its  banks,  and  carries 
them  along  with  it  (Fig.  21),  scratching  and  scoring 
with  them  the  stones  it  finds  lower  down  in  its  chan- 
nel. Where  the  end  of  the  glacier  melts,  these  bottom 
stones  are  left  in  a  curved  heap.  "When  from  change 
of  climate  the  glacier  ends  farther  up  the  slope  than 
it  once  did,  two  lines  of  stones  show  wThere  the  banks 
were.  In  the  picture  you  see  a  line  of  stones  down 
through  the  middle  of  the  glacier.  These  are  where 
two  glaciers  have  joined,  and  the  stones  mark  the 
joined  edges.  These  stones  are  always  worn  round 
by  the  grinding  and  rubbing  they  have  received,  and 


68  The  Earth  in  Past  Ages. 

are  called  "  muttoned  "  rocks  by  the  French,  because 
at  a  distance  they  look  like  the  round  backs  of  a  flock 
of  sheep;  they  are  scratched,  too,  in  straight  lines 
(Fig.  22). 


Fig.  22. — ROCK  SCRATCHED  BY  GLACIER. 
From  Lyell's  "Elements  of  Geology." 

These  glacier  signs  are  very  important  in  studying 
what  the  Ice-king  has  done  in  bringing  the  earth  to 
its  present  state.  Long  before  there  were  any  people 
to  write  about  them,  the  glaciers  were  writing  little 


The  Ice-king  at  Work.  71 

scraps  of  their  history  and  travels  on  the  stones,  as 
the  savages  did,  and  this  history  we  can  read  to-day. 

Sometimes  may  be  seen  a  very  curious  effect  that 
the  stones  have  upon  the  ice,  which  they  protect  from 
the  melting  rays  of  the  sun.  Each  block  of  stone  rests 
upon  a  pillar  of  ice  of  its  own  making.  The  stone  is 
like  the  top,  and  the  ice-pillar  like  the  stem  of  a  great 
toadstool  (Fig.  23). 

Icebergs,  you  know,  are  great  floating  mountains  of 
ice:  as  not  more  than  one -eighth  of  the  iceberg  is 
above  water,  you  can  guess  how  immense  some  of 
them  are.  They  are  really  only  the  snouts  of  arctic 
glaciers  which  have  pushed  themselves  into  the  sea 
without  melting,  and  been  broken  off  by  the  tides  and 
the  waves.  When  an  iceberg  gets  afloat  it  sometimes 
comes  as  far  south  as  Washington  before  it  is  broken 
up  and  melted.  Usually  they  melt  in  the  sea,  and 
then  rocks  are  deposited  at  the  sea-bottom ;  but  some- 
times they  run  aground,  and  then  on  the  soil  of  coun- 
tries far  to  the  southward  arctic  rocks  are  dropped. 
The  icebergs  and  glaciers  of  the  far  past  have  mixed 
up  things  very  much  in  this  way. 

In  Greenland  no  rain  falls — only  snow ;  there  are 
no  rivers  but  ice  rivers.  A  large  part  of  the  country 


72  The  Earth  in  Past  Ages. 

is  covered  by  a  great  sheet  of  ice,  nearly  half  a  mile 
thick,  slowly  travelling  to  the  sea,  and  there  launch- 
ing thousands  of  icebergs. 

Strewed  all  over  the  northern  part  of  our  continent 
— over  mountains,  hills,  valleys,  and  plains — is  a  layer 
of  glacier  stones,  scratched  and  "  muttoned,"  different 
from  the  rocks  below  them,  showing  that  once  a  sheet 
of  ice  covered  this  country  as  it  now  covers  Green- 
land. This  broke  up  into  separate  glaciers,  as  we  shall 
find  out  more  fully  after  a  while,  filling  the  valleys, 
as  the  Hudson  and  the  Susquehanna,  till  it  came  to  a 
climate  warm  enough  to  melt  the  ice. 

As  time  went  our  part  of  the  earth  grew  warmer. 
We  do  not  know  why ;  we  only  know  it  was  so.  The 
glaciers  were  driven  back  to  the  arctic  regions.  Our 
country  was  no  longer  a  wide,  barren  ice-field,  but  was 
getting  slowly  ready  for  the  day  when  God  should 
command  it  to  blossom  as  the  rose,  and  be  a  home  for 
His  children. 


CHAPTER  VII. 

PLANTS  AS  BUILDERS. 

BESIDES  the  forces  of  moving  water,  fire,  air,  and 
ice,  which  have  been  continually  shifting  and  rear- 
ranging the  materials  on  the  surface  of  the  earth,  we 
have  other  builders  at  work.  There  are  the  plants  and 
animals — things  that  have  lived  and  had  organs,  and 
so  are  called  organic  forces ;  the  others,  because  they 
have  never  lived,  are  called  inorganic,  or  not  organic. 

The  plants  and  animals  helped  to  build  up  the  layers 
of  the  earth,  but  they  did  so  without  meaning;  they 
just  lived  and  grew  and  died,  dropping  upon  the  soil, 
and  those  parts  that  did  not  soon  decay  —  like  the 
limbs  of  trees,  the  bones  or  shells  of  animals  —  were 
sometimes  covered  over  and  preserved  in  great  layers. 
This  same  process  is  going  on  now. 

In  Virginia,  near  where  Chesapeake  Bay  meets  the 
Atlantic  Ocean,  lies  a  Avonderful  forest,  different  prob- 
ably from  anything  you  have  ever  seen.  Tall  tree- 


74  The  Earth  in  Past  Ages. 

trunks  rise  out  of  the  dark  water  below,  and  stretch 
up  and  up  till  they  are  lost  in  the  great  matted  bed 
of  dark-green  leaves  and  boughs,  which  seem  as  if  they 
were  the  roof  of  a  cavern  above-ground.  It  is  always 
dim  and  dusky  beneath  this  roof,  even  at  noonday. 

Great  coils  of  grape-vines  bind  together  the  tree- 
trunks,  and  out  of  the  water  rise  the  cypress  knees- 
trunks  that  have  grown  up  and  then  turned  suddenly 
back  again  into  the  water.  These  serve  to  steady  the 
trees  and  keep  them  firm  in  the  wet,  insecure  soil. 
Tall  reeds  and  grasses  grow  up  between  the  trunks  of 
the  trees,  and  hanging  masses  of  solemn  gray  moss 
drape  their  boughs.  Here  and  there  the  surface  of 
the  sullen  water  is  broken  by  little  tussocks  of  grass. 

The  water  is  a  dark  coffee-color,  but  clear  and  spar- 
kling, and  sweet  to  the  taste.  Over  all  this  wilderness 
of  solemn  trees  and  dark  water  reigns  a  death-like 
stillness,  broken  only  by  the  humming  of  millions  of 
mosquitoes  or  the  splash  and  rush  through  the  water 
of  some  water-snake  or  venomous  moccasin  which  has 
been  sunning  itself  on  a  log,  and  drops  into  the  water 
on  your  approach.  Here  in  this  Dismal  Swamp  the 
battle  between  land  and  water  is  going  on.  The  land, 
aided  by  the  plants,  is  continually  gaining  ground. 


FIG.  24. — A   THOPICAL   MORASS. 


Plants  as  Builders.  77 

Into  the  water  the  leaves  are  always  falling,  the  dead 
boughs  from  the  trees,  the  dripping  gray  moss  and 
the  juniper  berries,  making  a  solid  mass  and  slowly 
filling  up  the  pools. 

The  water  has  the  power  of  keeping  the  leaves  from 
decaying  as  they  would  on  land.  This  water  is  a 
very  wonderful  thing.  Many  years  ago,  when  I  was 
a  child,  I  went  out  from  Norfolk,  Virginia,  to  see  the 
old  Avar-ship  Pennsylvania,  that  was  lying  near  the 
city.  One  of  the  ship's  officers  handed  me  a  glass  of 
what  I  took  to  be  brown  sherry  wine.  I  tasted  it, 
and  found  it  was  pure,  sweet  water.  This  was  the 
coffee-colored  water  of  the  great  Dismal  Swamp,  and 
it  will  keep  sweet  for  twenty  years  on  account  of  the 
juniper  berries  that  have  colored  it.  I  think  the  glass 
I  drank  had  been  something  like  that  time  in  the  hold 
of  the  ship. 

In  some  of  the  Louisiana  swamps  the  surface  of  the 
water  is  covered  for  many  thousands  of  acres  with  a 
growth  of  grass  and  plants,  making  what  is  called  a 
floating  prairie,  where  twenty  years  ago  there  was  an 
expanse  of  clear  water.  The  grass  grows  thicker  and 
thicker  every  year.  Sometimes,  when  this  floating 
prairie  gets  heavy  and  water-soaked,  it  will  all  sink 


78  The  Earth  m  Past  Ages. 

into  the  shallow  water  beneath.  When  this  has  hap- 
pened often  enough,  the  lake  of  the  past  will  have 
been  converted  into  a  soggy  swamp.  Willow -trees 
seem  to  come  up  of  themselves,  and  their  roots  bind 
more  firmly  together  the  slight  soil  and  grass  roots, 
and  the  land  is  born  out  of  the  water,  gaining  solidity 
and  firmness  year  by  year.  These  floating  prairies, 
when  the  grass  and  roots  and  earth  are  only  two  feet 
thick,  are  strong  enough  to  allow  a  man  to  walk  about 
with  ease,  though  they  are  floating  on  clear  water  sev- 
eral feet  deep  underneath. 

In  some  countries  —  Ireland,  for  instance,  where 
there  is  a  great  deal  of  rain — moss  and  small  plants 
growing  on  a  soft,  muddy  place  make  a  deep  coating. 
Each  year's  growth  is  packed  closely  down  on  the 
growth  of  the  year  before.  In  this  way  a  peat-bog  is 
formed.  In  the  open  air,  when  plants  perish,  they  dry 
up  and  blow  away,  or  decay,  and  so  are  lost ;  but  in 
the  peat -bogs  the  water,  like  that  of  the  Dismal 
Swamp,  preserves  things  that  drop  into  it.  Bog  oak, 
out  of  which  ornaments  are  sometimes  made,  is  oak 
that  has  been  preserved  in  the  water  and  turned  black 
and  hard  with  years,  but  is  perfectly  sound. 

About  a  hundred  years  ago  the  body  of  a  woman 


Plants  as  Builders.  79 

was  found  deep  down  in  an  Irish  peat-bog  almost  per- 
fectly preserved;  even  the  hair  and  skin  and  nails 
were  sound.  She  must  have  been  there  a  long,  long 
while,  for  on  her  feet  were,  not  shoes,  but  ancient 
sandals,  such  as  have  not  been  worn  for  hundreds  of 
years. 

The  solid  packings  of  moss  forming  peat  are  cut 
into  squares  and  dried,  and  then  used  to  burn  instead 
of  wood  or  coal  in  many  parts  of  Ireland.  This  peat 
is  coal  partly  formed.  When  it  is  pressed  very,  very 
hard  by  machinery  it  is  made  into  a  kind  of  coal  which 
burns  quite  well.  Some  of  the  peat-bogs  in  Europe 
were  formed  by  the  cutting  down  of  the  forests  by  the 
Romans.  The  trees  were  left  lying  where  they  fell, 
and  often  dammed  up  springs,  and  so  a  bog  was  formed 
which  in  the  eighteen  hundred  years  since  has  grown 
into  a  peat-bog. 

In  most  bogs  formed  in  this  way  the  peat  is  not 
pure  ;  it  is  mixed  with  mud  and  sand ;  but  in  some 
places,  as  in  the  swamps  along  the  Mississippi,  the 
water  has  been  strained  of  its  mud  before  it  reaches 
the  swamp,  so  the  peat  is  made  just  of  layers  and  lay- 
ers of  leaves  packed  together  by  the  water,  and  is  per- 
fectly pure. 


80  The  Earth  in  Past  Ages. 

Sometimes,  when  solid  continents  or  islands  have 
sunk  beneath  the  water,  whole  forests  have  gone 
down  with  them,  the  fallen  trunks  of  trees  and 
stumps  in  place;  the  dirt  has  sifted  over  these,  till 
new  land  has  formed  above  the  old,  new  forests  have 
grown  up  and  fallen  and  been  buried.  A  cut  through 
such  a  bed  may  be  seen  in  Figure  26 ;  the  layers  of 
sand  and  shells  between  the  layers  of  tree -trunks 
show  that  it  has  been  under  water  between-times. 

In  New  Jersey  there  are  great  buried  forests  of 
cedar  which  have  lain  there  for  centuries  uninjured. 
People  actually  mine  for  timber.  Some  of  the  tree- 
trunks  lie  fifteen  feet  underground.  One  of  these 
trunks,  which  had  lived  for  five  hundred  years,  as 
showred  by  the  yearly  rings,  was  underneath  another 
which  had  a  thousand  yearly  rings. 

In  Louisiana,  where  the  timber  grows  heavily,  great 
trees  are  often  torn  up  and  carried  down-stream  by 
sudden  and  heavy  floods.  These  get  wedged,  and  dam 
the  stream,  so  that  though  the  water  can  filter  through, 
everything  which  comes  floating  down  the  stream  is 
stopped  and  packed  together,  and  forms  great  natural 
rafts.  About  forty  years  ago  the  Government  had 
one  of  these  removed,  which  measured  ten  miles  long. 


Fig.  25 — MINING  FOE.  CEDAR  LOGS  IN  NEW  JERSEY 


OF    THE 

|   UNIVERSITY 

OF 


Plants  as  Builders. 


83 


seven  hundred  feet  thick,  and  eight  feet  high.  It  was 
covered  with  plants,  and  even  a  few  great  trees  sixty 
feet  high  were  growing  on  the  top. 


Fresh-water  calcareous  slate. 
Dirt-bed,  with  stools  of  trees. 


Fresh  water. 


Portland  stoue,  marine. 


Fig.  26.— SECTION  OF  CLIFF. 
From  Lyell's  "Elements  of  Geology." 

The  plants  we  have  been  talking  about  are  good- 
sized — some  of  them  large  trees ;  but  there  are  other 
earth-builders  among  plants  too  small  for  the  eye  to 
see.  These  are  very  wonderful  little  plants  ;  in  many 
ways  they  seem  more  like  animals  than  plants.  Each 
one  is  a  little  greenish  dot  of  jelly,  with  a  glassy  coat 
like  a  shell.  They  may  be  found  in  almost  any  water, 
but  it  takes  a  good  magnifying-glass  to  see  them.  I 
have  found  them  in  the  water  from  a  running  stream, 
in  a  spoonful  dipped  up  from  the  hollow  made  in  a 


84  The  Earth  in  Past  Ages. 

country  road  by  a  horse's  hoof,  or  in  a  way-side  pool. 
In  the  seas  and  lakes  and  rivers  of  the  Old  World 
these  little  creatures  lived  and  multiplied  and  died, 
dropping  to  the  bottom,  and  making  earth  of  their 
tiny  glassy  shells.  A  piece  of  this  earth  smaller  than 
an  ordinary  bullet  or  green  pea  would  have  in  it  over 
two  hundred  million  shells,  and  yet  this  earth  covers 
thousands  of  acres  several  feet  thick. 

Out  in  the  western  part  of  Yirginia,  only  about  a 
hundred  feet  below  the  top  of  one  of  the  highest 
mountains  in  the  State,  there  is  a  lake  nearly  a  mile 
long  and  a  quarter  of  a  mile  broad.  It  is  as  clear  as 
crystal,  and  if  you  take  a  boat  and  go  out  upon  its 
still  surface  you  will  probably  look  at  the  sky  or  the 
green  banks  till  some  one  says  to  you,  "  Look  down." 
Then  you  see  a  wonderful  thing.  Down  at  the  bot- 
tom of  the  water  is  a  dead  forest ;  the  trees  are  stand- 
ing up,  with  their  naked  branches  spreading  abroad  in 
the  water  far  below  you.  How  such  a  lake  can  exist 
so  high  up  it  is  difficult  to  guess.  The  water  must 
come  from  the  small  portion  of  the  mountain  above  it. 
Some  years  ago  an  old  man  said  that  he  remembered, 
about  seventy  years  before,  when  there  was  no  lake, 
only  a  valley  filled  with  trees.  How  or  why  the  lake 


Plants  as  Builders.  85 

came  no  one  seems  to  have  found  out,  though  many 
guesses  have  been  made.  It  is  thought  that  the  water 
which  drained  from  the  mountain  used  to  escape,  but 
that  the  way  of  escape  was  somehow  closed,  and  so 
the  water  filled  up  the  valley.  The  trees,  of  course, 
died,  but  the  water  kept  them  from  decaying  and 
being  lost.  I  do  not  know  of  any  other  place  in  the 
world  just  like  this ;  but  the  same  thing  may  have 
happened  long  ages  ago,  and  trees  in  this  way  have 
helped  to  be  earth-builders. 


CHAPTER   VIII. 

THE  BUILDERS   UNDER    THE  SEA. 

THE  Pacific  and  Atlantic  oceans,  where  the  water 
is  not  too  cold,  are  dotted  over  with  myriads  of  isl- 
ands of  a  very  peculiar  kind.  Many  of  these  islands 
can  be  found  upon  the  map,  but  a  great  multitude  of 
them  are  too  small  to  be  put  down. 

These  are  coral  islands,  and  they  are  formed,  little 
by  little,  by  tiny  living  beings,  some  of  them  so  small 
that  you  can  only  see  them  plainly  by  using  a  magni- 
fying-glass.  The  Florida  Keys,  the  Bermudas,  and 
other  islands  near  our  Southern  coasts  are  the  work 
of  the  coral  animal,  as  well  as  the  reefs  along  the 
Florida  coasts.  Many  of  the  islands  built  up  in  this 
way  are  ring-shaped — round,  or  oval,  or  irregular — 
but  enclosing  a  quiet  lake.  In  some  the  ring  is  in- 
complete, and  the  water  inside  it  is  a  landlocked  bay ; 
in  others  there  is  a  row  of  islands  which,  if  connected, 
would  make  a  ring.  The  Bermuda  Islands  are  such 
a  row. 


The  Builders  under  the  Sea. 
These  curious  islands  are  called  atolls. 


87 


The  land 

lies  low,  and  the  curved  strip  of  land  forming  the  isl- 
and bears  a  grove  of  feathery  palms  and  beautiful 
flowering  trees,  bordered  by  a  beach  of  pure  white 
sand.  Seen  from  above,  an  atoll  would  look  like  a 
gigantic  green  wreath  floating  on  the  bosom  of  the 
water  (Fig.  27). 

It  must  be  a  wonderful  thing  to  be  the  first  person 


Fig.  27.— ATOLL. 

who  has  visited  one  of  the  lovely,  lonely  atolls  of  the 
Pacific,  whose  only  inhabitants  are  birds.  Fifty  years 
ago  this  was  a  more  common  occurrence  than  it  is 
now,  when  the  seas  are  so  full  of  great  ships  and 
steamers,  as  well  as  smaller  craft,  that  most  of  them 
have  been  at  some  time  visited.  Professor  Dana,  who 
went  out  on  an  exploring  expedition  some  time  ago, 


88  The  Earth  in  Past  Ages. 

says  that  "  on  one  atoll,  where  no  natives  ever  dwell, 
the  birds  were  so  innocent  of  fear  that  we  took  them 
from  trees  as  we  would  fruit,  and  many  a  songster  lost 
a  tail  feather  as  it  sat  perched  upon  a  branch  appar- 
ently unconscious  that  the  world  contained  an  enemy. 
They  had  never  found  out  the  vow  of  eternal  enmity 
sworn  against  the  birds  by  the  boys.  Poor  little 
heathen  birds  !  How  they  did  need  a  missionary !" 

You  may  have  heard  of  the  coral  insect,  and  of  its 
wonderful  industry  in  building  up  great  islands  in  the 
sea,  as  if  coral  was  built  as  honey-comb  is.  The  coral 
animal  is  not  an  insect,  nor  anything  like  one,  and  it 
builds  the  coral  precisely  as  you  build  up  the  bones  in 
your  body.  It  is  a  sort  of  flower-animal,  shaped  like 
an  aster  or  an  anemone  or  a  daisy.  It  has  nothing  of 
the  flower  about  it  except  a  resemblance  in  shape,  but 
is  as  much  of  an  animal  as  an  oyster  or  a  fish.  The 
coral  polyp  has  a  thick  stem  crowned  by  a  row  of 
petal-like  arms  arranged  about  a  centre,  or  sometimes 
several  rows  so  arranged.  The  stem  is  the  body,  and 
in  the  upper  part  of  this  is  a  hollow  sac — the  stomach. 
The  centre  of  the  flower  is  the  mouth,  and  the  petals 
are  feeders  to  catch  and  draw  in  the  floating  food  that 
comes  within  reach.  Some  of  the  sea -anemones  do 


The  Builders  under  the  Sea. 


89 


not  make  coral,  and  others  do,  but  all  are  constructed 
on  this  simple  flower  plan  (Fig.  28,  a,  b). 

When  you  eat  and  digest  your  food,  new  particles 
of  flesh  are  formed.  These  are  pushed  in  between  the 
particles  already  there,  and  at  the  same  time  old  par- 
ticles which  are  dead  and 
of  no  further  use  to  you 
are  cast  off.  While  you 
are  growing,  more  new 
particles  are  made  than 
old  ones  are  cast  off .  When 
you  are  grown,  those  that 
are  taken  on  are  equal  to 
those  that  are  cast  off. 
This  constant  change  goes 
on  in  the  bones  as  well  as 
in  the  flesh,  though  more 
slowly. 

Such  a  change  is  all  the  while  taking  place  in  the 
coral  polyps.  The  coral  is  the  skeleton  of  the  polyp. 
Instead  of  the  skeleton  being  all  inside  the  polyp's 
body,  as  yours  is  in  you  (except  your  teeth),  or  all  out- 
side, as  it  is  in  the  oyster,  it  is  partly  in  and  partly 
out.  In  the  lower  part  of  the  stem  of  the  coral  ani- 


Fig.  28.  — CORAL  WITH  POLYPS. 


90  The  Earth  in  Past  Ages. 

mal,  below  the  stomach,  is  the  skeleton ;  as  the  polyp 
grows  it  keeps  adding  particles  to  its  skeleton,  and 
as  it  casts  off  less  than  it  adds,  the  skeleton  grows 
too  long  for  the  polyp,  and  is  left  behind  as  a  solid 
stem,  on  the  tip  of  which  is  the  flower-like  animal 
(Fig.  28,  a). 

The  polyp,  though  an  animal,  is  of  a  very  low  order. 
It  is  really  only  a  stomach,  a  mouth,  and  feeders.  Al- 
though it  has  no  eyes,  it  can  somehow  tell  when  its 
prey  is  near,  for  it  is  quick  to  reach  out  its  beautiful 
petal-like  arms  and  draw  it  in.  It  has  no  ears,  but 
the  softest  footfall  will  cause  it  to  draw  in  all  its  petals 
and  shrink  down  into  a  little  brown  knob  which  can 
scarcely  be  found  among  the  sea- weed  at  its  foot  (Fig. 
28,  J).  It  cannot  move  about,  for  it  is  fastened  tight 
to  its  coral  stem,  but  it  is  provided  with  a  wonderful 
contrivance  for  the  capture  of  the  prey  beyond  the 
reach  of  its  arms.  All  along  the  beautiful  petals  are 
thousands  and  thousands  of  tiny  pockets,  and  in  each 
one  is  coiled  up  a  long,  slender  thread.  Let  an  un- 
wary little  fish  come  within  range,  and  in  a  second 
hundreds  of  these  threads  are  shot  out,  each  turning 
itself  inside  out  as  it  comes.  The  threads  are  barbed 
and  poisoned,  and  svoe  to  the  fish  who  is  lassoed.  He 


The  Builders  under  the  Sea. 


91 


is  stunned,  and  soon  dies.  Then  the  victim  is  drawn 
into  the  innocent-looking  flower.  After  the  meal  is 
digested,  the  flower  turns  itself  wrong  side  outward, 
and  so  gets  rid  of  any  fish  bones  it  cannot  digest. 
Out  of  food  so  caught  and  digested  the  solid  coral  is 
formed.  A  single  polyp  would  form  only  a  small 
stem,  but  the  polyps  increase  by  sprouting  from  buds, 
or  by  one  of  them  stretching  and  splitting  up  into  two 
or  three  or  a  dozen  polyps,  till  great  branches  or  sheets 
of  them  are  formed  with  the 
coral  underneath.  The  shape 
of  the  clumps  or  branches  is 
determined  by  the  way  they 
increase  (Figs.  29  and  30). 

Reef -making  polyps  cannot 
live  in  the  depths  of  the  sea, 
but  when  they  lodge  near 
enough  to  the  surface,  and  in 
water  which  all  the  year  round 
is  never  cold  enough  to  kill 
them,  they  grow  steadily,  though  slowly,  and  increase 
enormously  in  numbers. 

All  through  the  Pacific  Ocean  these  curious  islands 
are  found.     They  are  of  three  kinds ;  either  an  ordi- 


Fig.  29. — CORALS. 

From  Lyell's  "Elements  of  Geol- 
ogy." 


92  The  Earth  in  Past  Ages. 

nary  island,  surrounded  by  a  pure  white  beach  made 
of  coral  sand,  or  an  island  with  a  ring  around  it,  or 
one  which  is  nothing  but  a  ring.  Sometimes  the 
beach  or  ring  is  broken  up — that  is,  some  parts  of  it 
do  not  rise  above  the  surface  of  the  water,  and  the 


Fig.  30. — CORALS. 
From  Lyell's  "Elements  of  Geology." 

ring  is   only  marked   by  dots   of  islands  arranged 
around  in  a  circle. 

Wherever  such  islands  occur  they  have  been  slowly 
built  up  by  coral  polyps.  When  the  clumps  of  coral 
have  grown  up  to  the  surface,  the  branches  are  broken 
off  by  the  waves  and  ground  into  powder  or  coral 


The  Builders  under  the  Sea.  93 

sand,  as  it  is  called  if  coarse,  and  coral  mud  if  finely 
ground.  This  powdered  coral  sinks  over  the  spread- 
ing branches  of  the  living  coral  and  finally  fills  them 
up,  and  with  shells  and  bones  they  heap  up  above  the 
surface  of  the  water  and  gradually  harden  into  rock. 

Below  the  water,  on  the  sloping  beach  that  runs 
out  towards  the  sea  for  a  little  distance,  you  may  see, 
if  you  look  downward,  a  wonderful  fairy  garden.  The 
polyps  sometimes  look  like  beautiful  animal  flowers, 
waving  their  fringe  of  feelers  like  leaves  with  every 
movement  of  the  water ;  other  fan-like  corals,  called 
gorgonias,  send  the  pink  lace- work  of  their  leaves  up 
through  the  water,  while  bright  fish  dart  in  and  out 
amid  the  curious  animal  forest,  showing  their  vivid 
colors  against  the  white  background  of  the  coral  sand. 

Many  of  the  polyps  are  too  small  to  be  seen  with- 
out a  magnify  ing  -  glass,  so  you  would  only  see  the 
clumps  and  trees  of  growing  coral  covered  over  with 
a  coating  of  a  soft,  fleshy  substance  if  you  looked  at 
them  through  the  water. 

The  peninsula  of  Florida,  on  the  south-eastern  end 
of  the  United  States,  is  a  land  made  by  the  coral 
polyps.  Several  reefs  have  been  built,  one  beyond 
the  other,  and  the  space  between  became  gradually 


94  The  Earth  in  Past  Ages. 

filled  up  with  drifting  sand  and  floating  wood,  till  the 
solid  land  was  formed.  There  are  still  reefs  beyond 
the  main-land  called  the  Florida  Keys. 

Just  why  reefs  should  form  as  they  do  in  lines  and 
rings  off  the  shore  of  the  land,  or  make  ring-shaped 
islands  in  mid-ocean,  is  not  absolutely  certain.  Years 
ago,  when  Mr.  Darwin  was  a  young  and  unknown 
man,  he  gave  the  first  explanation  that  seemed  really 
to  satisfy  men  of  science.  For  forty-five  years  these 
ideas  of  Darwin  were  believed  in  by  all  the  world,  but 
of  late  years  there  has  been  much  talk  and  much  study 
about  the  question,  and  geologists  are  divided.  All 
hold  the  same  facts — it  is  the  reasons  for  them  that 
they  cannot  agree  upon.  So  it  seems  to  me  wiser  to 
give  you  the  facts  only,  and  not  attempt  to  give  an 
explanation  that  may  not  prove  true. 

In  great  storms  near  the  coral  islands,  the  water 
often  looks  milky,  whitened  by  the  fine  coral  mud. 

In  shallow  seas  corals  often  grow  up  in  a  sort  ol 
umbrella  or  mushroom  shape,  with  a  central  stalk  and 
a  wide,  flat  top.  A  great  many  of  these  will  unite 
and  make  an  island,  held  up  by  great  columns  below. 
Sometimes  in  the  Pacific  a  ship  has  run  aground  on 
one  of  these  umbrella -shaped  reefs,  the  column  has 


The  Builders  under  the  Sea. 


95 


Fig.  31. — MAGNESIAN  LIMESTONE. 
From  Lyell's  "Elemeuts  of  Geology." 


broken,  and,  to  the  sur- 
prise of  the  crew,  the 
vessel  has  gone  safety 
ahead. 

There  are  many  other 
kinds  of  sea  creatures 
which  are  helping  to 
build  up  land  in  the 
bed  of  the  ocean.  Fish, 

large  and  small,  when  they  die,  drop  their  beautiful 
shells,  or  their  skeletons,  and  these  collect  in  the  sea 
depths,  and  after  a  while  become  packed  into  a  solid 
stone.  In  this  piece  of  limestone  (Fig.  31),  see  how 
closely  the  shells  lie  together;  in  other  pieces  there 
will  be  dozens  of  different  kinds  packed  in  the  broken 

bits  and  dust  made 
by  thousands  of  other 
shells  (Fig.  32). 

The  chalk  cliffs  of 
Dover,  which  gave  to 
England  her  poetic 
name  of  Albion  (from 
albus,  white),  are  solid 


Fig.  32.— FOSSILS  OF  CHALK. 
From  Lyel.'s  "  Elements  of  Geology.' 


masses  of  tiny  shells. 


96 


The  Earth  in  Past  Ages. 


At  the  bottom  of  the  Atlantic  there  are  to-day  form- 
ing just  such  beds  of  chalk,-  not  yet  made  into  a  solid 
mass,  but  on  their  way  to  be  (Fig.  33),  and  if  the  chalk 
which  was  made  ages  ago  and  that  which  is  making 
to-day  are  compared,  they  will  be  found  to  be  very 
much  the  same. 


Fig.  33. — FOSSILS  OF  CHALK. 
Prom  Lyell's  "Elements  of  Geology.5' 


CHAPTER   IX. 

THE   CRUST  OF  THE  EARTH. 

THE  earth,  as  you  know,  is  a  great  globe,  eight  thou- 
sand miles  through  from  side  to  side.  Geology  would 
not  be  a  possible  study  if  we  were  obliged  to  learn 
about  the  earth,  down  to  its  centre,  four  thousand 
miles  below  the  surface.  All  this  mighty  mass,  ex- 
cept a  sort  of  skin  which  encloses  it,  as  the  rind  en- 
closes an  orange,  is  made  up  of  metals  and  minerals, 
just  as  the  fire  has  moulded  them.  At  first  the  "  rind  " 
was  only  the  outer  part  of  the  globe  of  melted  rock, 
which  had  hardened  as  the  earth  cooled  down. 

You  remember  what  it  was  that  changed  the  hard- 
ened surface  of  the  globe  into  the  wonderful  layered 
crust  that  now  covers  it :  how  the  air  and  water  and 
fire  went  to  work,  the  air  and  water  powdering  the 
rock  and  letting  it  settle  into  the  water's  depths ;  and 
then,  when  this  had  again  become  solid,  how  the  im- 
prisoned fire  burst  through,  turning  and  tearing  and 
wrinkling  the  layers. 
•7 


98  The  Earth  in  Past  Ages. 

The  crust  of  the  earth,  so  far  as  we  know,  is  not 
more  than  ten  miles  deep  anywhere,  and  in  many 
places  is  not  more  than  three.  This  seems  a  wonder- 
ful depth  when  we  think  how  long  it  would  take  to 
walk  so  far,  but  it  is  very  little  when  compared  with 
the  size  of  the  earth. 

Of  course  we  could  never  have  reached  to  the  bot- 
tom layers  if  they  had  all  settled  quietly  down,  one 
on  top  of  the  other,  and  stayed  just  where  they  first 
settled,  for  the  deepest  mines  cut  down  through  only 
about  one  mile ;  but  fire  has  come  to  our  help,  and 
broken  and  tilted  them  up  so  that  the  edges  of  the 
layers  are  exposed,  and  can  be  studied  better  than  if 
men  had  dug  down  to  them. 

The  crust  of  the  earth  is  like  a  wonderful  book, 
with  its  leaf  upon  leaf,  close  shut,  yet  each  bearing 
upon  it  the  record  of  a  life  long  passed  away.  For 
hundreds,  even  for  thousands,  of  years  the  pages  of 
this  book  lay  unread.  Men  had  seen  them ;  they  had 
perhaps  guessed  and  wondered  at  the  curious  forms 
impressed  upon  them ;  but  no  one  had  looked  at  them 
with  a  seeing  eye,  no  one  had  worked  out  the  problem, 
no  one  had  guessed  the  riddle  of  the  rocks.  Under- 
neath these  written  pages,  where  the  history  of  the 


The  Crust  of  the  Earth.  99 

past  may  be  read,  lies  the  fire-made  rock,  like  so  many 
blank  pages.  No  life  had  ever  existed  there,  and  so 
the  pages  are  empty. 

The  crust  of  the*  earth  is  very  irregular ;  great 
mountains  and  plains  rise  above  the  level  of  the 
oceans,  and  mighty  valleys  sink  beneath  their  depths. 
The  highest  mountains  stand  only  about  five  miles 
above  the  sea-level,  and  the  deepest  ocean  valley  sinks 
only  about  the  same  distance  beneath  its  waters. 
Great  as  this  unevenness  of  the  surface  seems,  it  is 
less,  in  proportion  to  the  size  of  the  globe,  than  the 
roughness  of  its  rind  is  to  an  orange. 

When  you  look  on  the  map  of  the  world,  the  conti- 
nents appear  to  be  very  irregular  in  shape.  There 
seems  to  be  no  sort  of  rule  in  their  formation  ;  but 
there  is:  some  things  are  alike  in  them  all.  Each 
continent — Europe  and  Asia  being  one — is  surround- 
ed, or  nearly  surrounded,  by  water ;  the  mountains  run 
somewhere  not  far  from  the  rim,  making  of  each  a 
great  shallow,  irregular  basin,  and  the  highest  range 
of  mountains  is  nearest  the  largest  ocean.  In  North 
America,  for  example,  the  Pacific  Ocean  is  larger  than 
the  Atlantic;  the  Rocky  Mountains,  which  face  the 
Pacific,  are  higher  than  the  Eastern  ranges  that  face 


100  The  Earth  in  Past  Ages. 

the  Atlantic.     The  same  thing  is  true  of  the  other 
continents. 

During  the  struggle  of  the  imprisoned  giant,  Fire,  to 
make  his  escape,  many  changes  have  taken  place  in 
the  shape  of  the  land,  but  the  changes  have  been  a 


Figs.  34,  35. — RAIN-DROPS  AND  WORM-TRACKS  ON  GREEN  SHALE. 
From  Lyell's  "Elements  of  Geology." 

sort  of  growth  or  development ;  the  continents  have 
gradually  become  larger,  the  land  has  slowly  been 
lifted  up  out  of  the  water. 

Layered  rocks  are  of  as  many  kinds  as  there  are  of 
sea-shores  and  lake-bottoms.     Some  .of  them  are  fine 


The  Crust  of  the  Earth. 


101 


mud,  some  sand,  some  pebbles,  and  some  broken  bits 
of  stone  or  coral  cemented  together  and  hardened  into 
rock.  A  layer  has  often  been  traced  from  its  condi- 
tion as  mud  or  sand  to  the  place  where  it  is  a  layer 
of  solid  rock,  with  all  the  dif- 
ferent stages  of  change  be- 
tween. 

In  the  layered  rock  sea- 
shells  lie  just  as  they  lie  in  the 
water's  bottom.  You  remem- 
ber how  Hugh  Miller  saw,  on 
the  slab  of  sandstone  his  ham- 
mer laid  open,  ripple  marks 
such  as  he  had  often  seen  in 
the  sands  of  Cromarty  Frith, 
and  he  knew  he  had  come 
upon  an  ancient  sea-beach. 

Think  how  strange  it  must 

seem  to  lift  one  la}^er  of  rock  from  another  and  find 
there  the  impression  of  rain-drops — the  record  of  a 
rain-storm  that  had  swept  over  some  lonely  sea-shore 
millions  of  years  ago,  which  yet  is  as  clearly  to  be 
read  as  if  the  drops  had  fallen  yesterday  (Figs.  34,  35). 

Earth,  or  sand,  has  been  changed  into  solid  rock  in 


Fig.  36. — A  DISTORTED  SHELL. 


102 


The  Earth  in  Past  Ages. 


several  ways ;  sometimes  it  has  been  slowly  baked  by 
the  inner  fires,  somewhat  as  clay  is  baked  into  brick 

in  a  kiln.  At  other 
times  it  has  been  pressed 
into  stone  by  the  enor- 
mous weight  of  the  lay- 
ers on  top  of  it.  Shells 
are  found  in  rock  which 
has  been  made  in  this 
way  pressed  into  cu- 
rious shapes  (see  Fig. 
30).  The  upper  one  of 
these  shells  (a)  has  its 
natural  shape ;  the  low- 
er is  the  form  into  which 
it  was  pressed  by  the 
weight  above. 

In  Figure  3Y  you  see 
a  shell  on  the  inside 
of  which  some  curious 
worm -like  cases  are 

glued.  The  dead  oyster -shell  must  have  lain  long 
enough  on  the  bottom  of  the  sea  for  the  sea-worm 
to  have  built  its  case,  which  it  takes  some  time  to 


Fig.  37. — SEA- WORM  ON  OYSTER-SHELL. 
From  Lyell's  "Elements  of  Geology." 


The  Crust  of  the  Earth.  103 

do,  before  the  earth  settled  over  and  enclosed  them 
both. 

It  is  very  easy  to  see  that  when  one  layer  of  earth 
settles  over  another  the  rock  would  easily  split  in  that 
direction  ;  but  rocks  split  in  other  directions  too  (Fig. 
38).  You  see  there  are  three  different  sets  of  lines  in 
these  rocks,  and  the  rock  will  split  along  either  of 
these.  A  and  B  are  the  layers  formed  by  settling; 


Fig.  38. — STRATIFICATION,  JOINTS,  AND  CLEAVAGE. 
From  Lyell's  "Elements  of  Geology." 

C  is  one  of  the  cracks  made  by  the  shrinking  of  the 
rock  as  it  cooled  ;  but  the  other  lines,  diagonal  to 
these,  are  formed  by  heavy  pressure.  If  you  take 
such  a  thing  as  beeswax  or  white -lead  and  put  it 
under  heavy  pressure,  it  will  come  out  in  such  a  con- 
dition that  you  can  easily  separate  it  into  sheets. 


104  The  Earth  in  Past  Ages. 

Slate  that  is  used  for  the  roofs  of  houses  is  stone 
which  has  been  put  under  such  heavy  pressure,  while 
it  was  hardening,  that  it  came  out  as  beeswax  or 
white -lead  would,  and  will  split  into  thin  sheets. 
The  pressed  and  distorted  shells  in  Figure  36  are  fre- 
quently found  in  rock  like  this,  and  the  shells  are  al- 
ways pressed  out  of  shape  in  the  same  direction  as 
the  cleavage  of  the  slate,  no  matter  in  what  position 
they  had  fallen,  showing  that  there  was  no  accidental 
distortion  in  the  form  of  the  shell. 


CHAPTER  X. 

M 0  UNTA  IN-BUILDING. 

THE  most  beautiful  scenery  on  the  face  of  our  earth 
owes  its  beauty  in  great  part  to  the  presence  of  mount- 
ains. Whatever  may  be  said  for  the  beauty  of  ocean 
scenery  by  its  lovers,  it  is  still  true  that  the  mountains 
divide  the  honors  with  the  sea. 

Mountains  have  been  formed  in  different  ways,  and 
are  different  in  their  appearance,  but  each  possesses  a 
beauty  of  its  own.  The  soft-swelling,  forest-crowned 
domes  of  the  Blue  Ridge  and  Alleghanies,  in  the  East, 
are  scarcely  less  beautiful  than  the  majestic  snow- 
crowned  peaks  of  the  Rockies,  in  the  West. 

The  real  mountain  -  builders  of  the  world  are  the 
earth-builders,  fire  and  water ;  and  the  different  ways 
in  which  the  work  was  done  came  from  the  various 
combinations  of  these  forces.  After  the  water  had 
done  its  work  in  depositing  the  layers,  one  on  top  of 
the  other,  under  the  sea,  a  change  would  come — the 


106  The  Earth  in  Past  Ages. 

hardened  crust  would  be  slowly  wrinkled  up  by  the 
shrinkage  of  the  globe  beneath.  This  shrinking  was 
in  part  due  to  the  cooling  of  the  melted  portion  in  the 
interior,  and  part  probably  to  the  escape  of  gases  and 
water  in  the  form  of  vapor.  The  skin,  or  crust,  that 
would  fit  smoothly  over  the  larger  globe  would  natu- 
rally wrinkle  over  the  globe  that  had  become  smaller. 


Fig.  39. — SECTION  ILLUSTRATING  THE  STRUCTURE  OF  THE  Swiss  JURA. 
From  Lyell's  "Elements  of  Geology." 

Such  wrinkles  are  our  mountain  chains  as  they  first 
appeared.  Some  mountains  are  still  little  more  than 
such  wrinkles,  with  the  layers  unchanged  (Fig.  39). 
In  the  picture  we  see  just  how  the  layers  follow  the 
curves  of  the  mountain.  A  great  cleft  has  been  made 
through  the  three  wrinkles,  or  mountain  ranges,  and 
this  enables  one  to  see  just  how  the  layers  run  in  the 


Mountain  -  building.  107 

two  left-hand  peaks.  In  the  right-hand  range  water 
has  come  in  and  cut  through,  and  lowered  the  mount- 
ain-top. Fire  is  the  cause  of  mountain-building,  either 
directly  or  indirectly ;  while  water  carves  and  sculpt- 
ures and  wears  away  in  various  ways  the  simple  folds 
or  wrinkles  as  first  made. 

First  we  will  try  to  understand  just  how  the  crust 
of  the  earth  is  thrown  into  wrinkles.  Take  a  dozen 
pieces  of  cloth  or  flannel,  cut  them  the  same  shape  and 


Fig.  40. — WRINKLED  LAYERS. 

size,  and  lay  them  on  the  table  in  an  even  pile,  put  two 
books  at  the  ends,  as  you  see  in  the  picture  (Fig.  40),  and 
one  on  top  to  hold  them  in  place ;  now  press  the  two 
standing  books  gently  towards  each  other,  and  the 
cloth  will  wrinkle  up,  the  layers  still  lying  on  top  of 
each  other,  or  conformably,  as  it  is  called.  An  experi- 


108  The  Earth  in  Past  Ages. 

ment  has  been  made  with  layers  of  moist  clay,  put 
one  above  the  other  in  a  pile,  a  weight  placed  on  top, 
and  then  pressed  as  the  flannel  is,  gently  together. 
When  the  open  sides  are  watched  the  layers  of  clay 
are  seen  to  wrinkle  up,  just  as  they  did  ages  ago  in 
the  formation  of  mountain  chains ;  where  the  pressure 
is  great,  many  wrinkles  are  formed  side  by  side,  with 
valleys  between,  as  in  the  case  of  the  Rockies  and 
Cordilleras  and  our  Eastern  mountains. 

The  Alleghanies  and  Blue  Ridge,  as  well  as  the 
White  and  Green  mountains  of  our  Eastern  States, 
have  been  made  by  such  a  crumpling  of  the  earth's 
crust,  followed  by  the  action  of  water  and  ice.  The 
rains  have  washed  and  worn  away  the  crumbled  rock; 
the  air  and  the  ice  have  helped  to  do  the  work,  till 
the  original  forms  of  these  mountains  have  all  been 
changed. 

One  of  the  most  singular  mountains  in  the  world 
has  been  made  entirely  by  the  action  of  water  (Fig. 
41).  The  layers  of  rock  running  across  the  mount- 
ain look  as  if  they  had  been  built  by  a  stone-ma- 
son, and  the  little  cones  of  washed  earth  as  though 
they  had  been  sculptured  out  of  the  rock  by  tools. 
These  have  been  built  and  sculptured  too,  but  they 


Mountain  -  building. 


109 


Fig.  41. — PYRAMID  MOUNTAIN. 
Prom  Reclu^'s  "Earth." 


have  been  done  by  water,  and  not  by  the  hand  of 


man. 


From  the  kind  of  layers  forming  mountain  ranges 
and  the  shells  and  bones  found  in  them,  it  is  known 
that  the  part  of  the  earth's  crust  which  was  forced  up 
into  wrinkles,  as  the  inner  portions  of  the  globe  con- 


110  The  Earth  in  Past  Ages. 

traded,  lay  along  the  sea-bottoms,  but  near  the  coasts. 
There  were  reasons  why  the  earth's  crust  here  was 
softer  than  elsewhere,  and  it  gave  Avay  along  its  weak- 
est lines. 

Of  course  this  solid  crust  has  cracked  and  broken 
under  the  strain.  In  some  places  these  cracks  have 
been  widened  by  water  flowing  through  them,  and  as 
a  result  we  have  the  deep  clefts  in  the  rocks,  with 
streams  running  through  the  bottom  of  them  that  are 
called  canons  (pronounced  canyons)  (Fig.  42).  No  pict- 
ure can  give  an  idea  of  these  wonderful  walls  of  rock 
rising  up  on  each  side  of  the  stream  running  along 
at  the  bottom,  sometimes  thousands  of  feet  high. 

Where  the  crust  of  the  earth  is  cracked  through  by 
the  action  of  fire,  one  half  will  sometimes  settle  lower 
than  the  other,  and  then  the  crack  will  close  up.  Of 
course,  where  this  is  the  case  the  layers  will  no  longer 
match.  This  is  called  a  fault  by  miners,  who  are 
very  much  troubled  when  they  are  engaged  in  dig- 
ging out  a  layer  of  coal  or  iron,  and  suddenly  find  it 
end  in  a  blank  wall  of  rock.  They  know  that  this  is 
a  fault,  and  that  the  layer  they  want  to  follow  is  either 
above  or  below  them.  A  knowledge  of  geology  is  a 
great  help  in  determining  which  way  they  shall  work 


Mountain  -  building.  113 

in  trying  to  find  the  lay- 
er, or  vein,  they  have  lost 
by  the  fault. 

The  causes  that  are 
changing  the  earth's  sur- 
face to-day,  as  you  know, 
are  the  very  same  that  Fis-  43.— FAULTS. 

were  at  work  changing  it  From  Hooker'8  "o^T'aloffy  and  Geol~ 
in  the  past ;  but  we  must 

remember  that  there  is  a  difference  between  the  past 
and  the  present.  The  earth's  crust  was  thinner  then, 
and  the  forces  struggling  under  it  were  stronger;  so 
we  should  expect  some  difference  in  the  results. 

There  are  places  on  the  face  of  the  earth  where  the 
rocks  gave  way,  and  the  melted  stone  has  broken 
through  the  weakest  spots,  and  flows  out  as  lava. 
These  are  volcanoes.  In  the  past  it  seems  probable 
that  the  fire  and  lava,  gases  and  steam,  poured  out 
not  only  in  spots,  but  along  lines  ;  that  there  were  long 
cracks  and  iissures  through  which  the  interior  fires 
escaped.  In  the  far  West  there  are  vast  tracts  of  land 
covered  with  sheets  of  lava  nearly  half  a  mile  thick, 
which  it  soems  impossible  the  few  extinct  volcanoes 
there  COM  Id  have  poured  out.  The  Cascade  and  Sierra 
8. 


The  Earth  in  Past  Ages. 

ranges  seem,  to  be  built  up  by  the  outpouring  of  lava 
along  their  lines. 

This  country  was  the  scene  of  a  terrible  eruption ; 
but  now  there  is  not  a  single  active  volcano  left.  The 
hot  springs  and  geysers  are  all  that  is  left  to  bear 
witness  to  the  almost  exhausted  force  of  the  fire  that 
once  did  such  a  mighty  work  there  in  mountain-build- 
ing. 


CHAPTER  XL 
METALS  AT  HOME. 

THE  crust  of  the  earth  is  made  up  of  many  other 
things  besides  layered  stone,  and  very  valuable  things 
they  are,  too.  Gold  and  silver,  iron  and  copper,  lead 
and  tin,  as  well  as  many  other  metals,  are  found  among 
the  rocks. 

Iron  is  really  the  most  valuable  of  the  metals.  We 
are  accustomed  to  think  that  gold  is  more  valuable 
because  it  will  bring  a  higher  price.  But  think  for 
yourself,  and  you  will  see  what  thousands  of  useful 
things  are  made  of  iron  and  steel,  and  how  very  few 
real  uses,  apart  from  money,  gold  has.  Nothing  else 
is  so  good  for  filling  teeth,  a  mixture  of  gold  is  used 
in  some  kinds  of  photography,  and  gold  is  valuable 
for  coins  because  it  does  not  rust  or  corrupt ;  but  its 
real  uses  are  not  many. 

If  you  were  cast  away  on  a  desert  island,  which 
would  you  choose  to  find,  a  bag  of  gold  or  a  case  of 


116  The  Earth  in  Past  Ages. 

tools  ?  One  single  knife  would  outweigh  in  value  all 
the  gold  you  could  carry.  Comparing  the  two  metals 
in  such  a  way  as  this  makes  us  see  how  much  more 
really  valuable  iron  is  than  gold.  Savages  of  all  coun- 
tries have  made  their  first  metal  tools  of  copper,  or  a 
mixture  of  copper  and  other  metals,  called  bronze. 
This  is  because  copper  is  found  in  a  purer  state  than 
iron,  and  is  softer,  so  that  it  is  more  easily  obtained, 
and  more  readily  worked  with  the  simple  tools  that 
savages  use.  So  you,  in  your  desert  island,  if  not  a 
savage,  at  least  living  the  life  of  a  savage,  might  pre- 
fer the  softer  metal,  because  you  probably  would  not 
have  the  means  of  separating  from  its  ore  the  harder 
metal,  or  of  working  it.  In  reading  about  savage  peo- 
ple you  often  hear  of  gold  and  silver  and  copper,  but 
never  of  iron,  and  this  is  the  reason. 

Gold  and  platinum  are  always  pure,  copper  and  sil- 
ver sometimes  so,  but  are  also  sometimes  found  in 
the  condition  of  ore.  Ore,  correctly  speaking,  is  a 
mixture  of  one  or  more  metals  with  earth  or  other 
mineral  matter.  This  is  not  a  common  mixture,  such 
as  you  could  make  by  stirring  salt  and  sugar  together, 
but  is  a  union  of  another  kind,  a  chemical  union,  by 
which  two  things  may  be  so  united  as  to  form  a  new 


.  44. — SCENE  AT  AN  IRON  MINE. 


Metals  at  Home.  119 

substance  unlike  either  of  the  two  out  of  which  it  has 
been  made.  Air  is  a  mixture  of  several  gases ;  water 
is  several  gases  in  chemical  union.  Air  remains  a  gas, 
but  water  is  utterly  unlike  a  gas — it  is  a  liquid. 

You  often  hear  of  gold  ore,  but  it  is  not  truly  an 
ore ;  the  pure  gold  is  mixed  with  other  minerals  or 
metals.  Iron  ore  is  a  chemical  union  of  iron  and  other 
things — one  of  the  gases  of  the  air  and  water,  for  ex- 
ample. Iron  ore  of  a  common  kind  is  iron  rust;  the 
solid,  heavy,  black  metal  has  been  turned  into  red, 
powdery  dust. 

If  you  have  travelled  much  you  have  probably  no- 
ticed how  very  red  in  some  places  the  earth  is ;  the 
mountain  land  in  Virginia  and  many  parts  of  New 
Jersey,  for  instance,  is  like  this.  I  have  seen  the 
ground  in  Virginia  look  fairly  crimson  in  the  sun- 
light. This  red  look  of  the  earth  means  iron,  and  iron 
well  rusted  at  that. 

Underneath  bogs  and  SAvamps  great  flat  cakes  of 
iron  ore  are  found,  sometimes  as  large  as  the  swamp, 
and  one  or  two  feet  thick.  This  collects  in  a  very  cu- 
rious way.  The  rusted  iron,  which  is  scattered  all 
through  the  earth,  will  not  dissolve  in  pure  water ;  but 
when  matter  that  has  once  been  living,  either  vegeta- 


120  The  Earth  in  Past  Ages. 

ble  or  animal,  decays,  it  changes  the  water  that  flows 
through  it  on  its  way  down  through  the  crust  of  the 
earth,  so  that  the  iron  rust  dissolves  in  it.  This  is 
carried  down  till  it  reaches  some  layer  of  earth  or  rock 
which  the  water  cannot  get  through.  There  it  settles, 
and  in  the  course  of  years  a  great  flat  bed  of  iron  ore 
is  formed. 

Iron  is  often  to  be  found  somewhere  near  these 
great  beds  of  decaying  vegetable  matter ;  it  is  gener- 
ally found  very  near  the  coal-fields,  and  these  were 
once  great  forests.  Time  and  heat  and  pressure  have 
changed  them  from  wood  into  coal. 

A  great  deal  of  labor  is  required  to  dig  the  iron  ore ; 
mighty  derricks  lift  it,  vast  furnaces,  white  hot,  are 
waiting  to  smelt  it,  and  so  separate  the  iron  from  the 
useless  matter  in  the  ores.  Life  near  an  iron-mine  is 
very  curious  and  interesting. 

In  CornAvall,  at  the  south-western  point  of  England, 
are  to-day  the  same  mines  that  were  worked  before 
the  birth  of  Christ.  The  Phoenicians,  who  were  the 
seafaring  men  of  those  days,  used  to  come  to  England 
— Albion  they  called  it,  because  of  the  white  chalk 
cliffs  along  the  southern  coast— to  get  the  copper  and 
tin  from  these  mines.  Some  of  them  have  been  dug 


Fig.  45. — PLACER  MINING. 


OF   THE 

«    UNIVERSITY 


Metals  at  Home.  123 

down  and  out  so  that  they  run  under  the  bed  of  the 
sea,  and  when  there  is  a  storm  the  miners  can  hear 
the  great  waves  hurling  themselves  on  the  rocks  and 
breaking  in  thunder  above  their  heads. 

In  these  Cornwall  mines  are  found  tin  and  copper 
in  some  places,  and  iron  and  lead  in  others.  A  very 
curious  thing  has  been  discovered  about  them :  all  the 
tin  and  copper  mines  run  east  and  west,  while  all  the 
lead  and  iron  run  north  and  south. 

The  layered  crust  of  the  earth,  as  we  know,  has 
been  many  times  upheaved  and  heated  and  cracked 
by  the  fires  beneath.  Sometimes  the  melted  stone 
ran  up  and  filled  these  cracks,  and  hardened  there,  as 
the  basalt  did  making  Fingal's  Cave  and  other  won- 
derful formations ;  sometimes,  as  we  have  seen,  the 
cracks  closed  after  one  side  had  slipped  and  sunk 
down,  so  that  the  layers  on  one  side  did  not  match 
those  on  the  other.  The  rocks  have  been  broken  and 
healed  again  till  they  are  all  seamed  and  scarred. 
Many  of  the  cracks  were  not  filled  at  once  with  melt- 
ed stone,  and  did  not  close.  These  were  gradually 
filled  later.  The  hot  waters  of  that  ancient  world, 
full  of  dissolved  metals  and  minerals,  dripped  and 
oozed  through  the  cracks,  leaving  behind  part  of  the 


124  The  Earth  in  Past  Ages. 

material  which  they  had  dissolved,  till  each  crack  was 
filled.  These  are  called  veins,  and  are  filled  some- 
times with  gold,  sometimes  with  silver  or  other  met- 
als, and  sometimes  with  minerals.  The  beautiful  stri- 
ping of  agate,  for  instance,  comes  from  such  a  cause. 
All  metal  veins  are  supposed  to  have  been  formed  in 
this  way. 

The  quantity  of  gold  in  circulation  was  not  very 
great  till  about  forty  years  ago,  when  gold  was  found 
in  many  places  nearly  at  the  same  time.  Our  West- 
ern country  and  Australia  were  both  settled  in  a  won- 
derfully short  time,  because  of  the  rush  to  the  gold 
and  silver  fields  after  the  precious  metals  had  been 
discovered  there. 

Mining  for  gold  is  in  some  respects  very  peculiar 
and  interesting.  The  metal  being  pure,  it  lies  embed- 
ded in  a  clear  whitish  stone  called  quartz.  You  have 
probably  seen  Indian  arrow-heads  which  have  been 
chipped  out  of  this  stone,  and  know  its  look.  Gold  is 
found  with  other  metals  and  minerals,  but  it  oftenest 
occurs  in  quartz.  The  falling  of  rocks,  the  rattling 
about  in  the  mountain  torrents  of  broken  bits  of  gold- 
bearing  quartz,  have  turned  the  stone  fragments  into 
pebbles,  and  set  the  gold  grains  free. 


^fc 


Metals  at  Home.  127 

The  first  of  the  Western  miners  used  to  shake  this 
gravel  in  pans,  and  the  gold  grains,  being  heavier, 
would  sink  and  be  afterwards  collected.  The  common 
slang  expression,  to  "pan  out  well,"  came  from  this 
method  of  collecting  gold.  This  was  called  placer 
mining.  Then  the  cradle,  with  water  running  through 
it,  was  used  as  an  improvement  upon  the  earlier  meth- 
od. This  also  soon  proved  too  slow  for  our  American 
haste  to  get  rich. 

Change  after  change  was  introduced,  each  as  an  im- 
provement upon  the  last,  till  a  new  method,  called  hy- 
draulic mining,  was  adopted  in  the  end.  It  is  called 
hydraulic  from  hydra,  water,  because  water  does  the 
greatest  part  of  the  work. 

To  understand  just  how  it  is  done  we  must  get  a 
clearer  idea  of  the  state  in  which  gold  is  usually  found. 
There  are  some  gold-mines  where  the  gold  is  shut  up 
in  the  solid  quartz,  and  has  to  be  dug  for  and  taken 
out  of  the  solid  rock  as  the  kernel  is  taken  out  of  the 
nutshell.  But  most  of  the  gold  in  the  world  is  in 
among  the  broken  fragments  of  rock  and  pebble  banks 
which  fill  the  beds  of  old  rivers  now  dry.  By  the  old 
mining  methods  these  were  painfully  dug  out,  washed, 
and  the  gold  collected. 


128  The  Earth  in  Past  Ages. 

Now  the  water  digs  the  ore,  washes  it,  and  separates 
it.  A  great  engine,  looking  like  a  cannon  more  than 
anything  else,  shoots  an  immense  stream  of  water 
against  the  gravel -bank,  wearing  it  aivay,  bringing 
down  great  quantities  of  stone  and  pebbles,  with  the 
gold  in  grains  and  threads  among  it.  The  stream  is 
so  strong  that  enormous  rocks  weighing  thousands  of 
pounds  are  tossed  in  the  air  as  though  they  were  pieces 
of  wood,  and  an  avalanche  of  stones  is  carried  in  the 
water  as  it  rushes  down  the  slope.  The  heavier  gold 
grains  drop  as  the  mass  moves  on. 

In  one  way  this  kind  of  mining  has  proved  a  great 
curse  to  the  country.  In  more  than  one  place  whole 
river-beds  have  been  so  choked  with  the  rocks  and 
earth  that  when  the  water  rises  in  spring  terrible 
floods  come,  and  the  whole  country  is  covered  with 
the  powdered  stone,  the  crops  are  killed,  and  the  soil 
very  much  injured ;  towns  are  almost  ruined,  and  farm 
buildings  totally  destroyed.  The  greatest  efforts  have 
been  made  to  put  a  stop  to  hydraulic  mining  by  law, 
and  there  is  no  telling  where  the  fight  will  end,  and 
who  will  be  the  victors  in  the  contest. 


CHAPTER  XII. 
A  STUDY  OF  BONES. 

I  HAVE  been  trying  to  take  you  with  me,  while  we 
looked  into  all  the  forces  and  agencies  that  have  been 
building  up  the  earth  and  bringing  it  to  the  condition 
which  we  now  know.  This  is  one  kind  of  geology- 
it  is  called  structural,  because  we  are  by  it  learning 
about  the  structure,  the  building,  of  the  earth.  Now, 
I  want  you  to  begin  in  another  way,  and  we  will  fol- 
low the  different  forms  of  life  in  the  vegetable  and 
animal  world  as  they  followed  one  another,  begin- 
ning with  the  simplest  creatures — such  mere  lumps 
of  jelly  that  it  is  hard  to  tell  whether  they  belong 
to  the  animal  or  vegetable  kingdom.  Such  a  study 
as  this  of  the  life  of  the  past  is  called  historical 
geology. 

Long  before  the  science  of  the  earth  was  thought 
of,  a  careful  study  had  been  made  of  living  animals 
and  plants.  To  do  this  properly,  and  make  it  easy  to 
9 


130  The  Earth  in  Past  Ages. 

remember,  they  were  arranged  in  different  classes. 
Everything  in  the  world  is  in  this  way  divided  into 
three  kingdoms — animal,  vegetable,  and  mineral.  Take 
one  of  these  kingdoms — the  animal,  for  instance,  to 
make  the  divisions  clear — and  we  find  it  divided  into 
four  grand  divisions.  The  lowest  of  these  is  the  Ka- 
diates ;  that  is,  creatures  tliat  have  no  backbone,  but 
which  are  formed  by  rays  going  out  from  a  centre, 
like  star-fish  and  coral  polyps.  (2)  The  Mollusks,  or 
shell -fish,  like  oysters  and  clams.  (3)  Articulates, 
insects ;  and  (4)  Vertebrates,  things  with  backbones. 
Under  these  divisions  come  what  are  called  classes. 
Under  the  backboned  animals  are  four  classes :  fishes, 
reptiles,  birds,  and  mammals.  Under  the  classes  are 
orders ;  under  the  orders,  families ;  under  the  fami- 
lies, genera ;  under  the  genera,  species ;  under  the 
species,  varieties.  To  make  it  simpler,  and  to  have 
something  to  look  back  to  if  you  are  in  doubt,  I  will 
write  these  in  a  list  just  in  the  order  in  which  they 
come.  By  the  side  of  these  divisions  I  classify  you 
to  give  you  a  notion  what  it  means.  I  do  not  know 
your  name  nor  where  you  live,  but  I  shall  just  imag- 
ine that  your  name  is  John  Smith,  that  you  live  in 
New  York,  and  belong  to  the  white  race. 


A  Study  of  Bones.  131 

John  Smith  belongs  to : 

1.  Kingdoms Animal  kingdom. 

2.  Divisions Mammal  division. 

3.  Classes Human  class. 

4.  Orders Caucasian,  or  white,  order. 

5.  Families American  family. 

6.  Genera New  York  genera. 

7.  Species Smith  species. 

8.  Varieties John  variety. 

Of  course  this  is  not  correct,  but  it  is  near  enough 
the  truth  to  make  it  easy  to  understand  what  is  meant 
by  classifying  an  animal  or  plant. 

This  arrangement  into  these  divisions  is  not  merely 
made  for  use — though  it  is  very  useful — it  is  rather  a 
finding  out  of  a  truth  than  the  invention  of  a  system. 

When  geology  began  to  be  studied,  it  was  gradually 
found  out  that  beings  bad  come  into  existence — that 
they  were  found  in  the  rocks — in  almost  the  same  or- 
der in  which  scientific  men  had  already  arranged  them. 
Science  is  not  the  making  up  of  a  system,  it  is  the  dis- 
covery of  something  that  already  existed. 

George  Cuvier,  a  Frenchman  who  lived  and  labored 
about  one  hundred  years  ago,  made  a  general  study 
of  bones.  He  found  that  between  the  different  bones 


132  The  Earth  in  Past  Ages. 

in  animals'  bodies  there  is  a  curious  relation ;  so  that 
when  one  bone,  say  a  tooth,  is  different  from  the  usual 
form,  you  may  expect  to  find  the  foot  different  too. 
We  do  not  understand  the  reason  why  this  should  be 
so ;  we  only  find  that  it  is  so  as  a  matter  of  fact. 
When  such  facts  as  these  are  found  to  exist  always, 
they  are  written  out  in  a  short  and  general  form  and 
are  called  natural  laws. 

By  studying  the  great  number  of  skeletons  of  ani- 
mals which  still  exist,  Cuvier  was  able  to  find  out 
what  parts  changed  together ;  that  is,  he  found  out 
the  rule  which  God  had  made  for  himself  in  creating 
life.  After  long  years  of  such  study,  Cuvier  could  tell 
just  what  animal  a  bone  belonged  to  when  he  saw  it. 
This  knowledge  was  a  wonderful  help  to  him  when 
he  began  to  study  the  bones  of  unfamiliar  animals — 
the  bones  dug  out  of  the  rocks.  He  did  not  have  all 
the  bones  of  any  one  kind  of  animal  to  fit  together 
like  the  pieces  of  a  dissected  map.  He  did  not  even 
have  all  the  bones  of  a  large  number  of  animals  to 
arrange.  If  he  had,  the  puzzle  would  have  been  only 
like  a  great  many  hard  dissected  maps,  all  jumbled  up 
together,  which  he  had  to  sort  out  and  put  together 
correctly.  This  would  have  been  hard  enough,  but 


A  Study  of  Bones.  133 

his  puzzle  was  harder  still.  He  would  have  one  bone 
from  one  animal,  and  another  from  another  animal  of 
a  somewhat  different  kind,  and  from  these  he  had  to 
make  out  what  both  kinds  of  creatures  from  which 
they  came  were  like. 

In  his  own  words,  translated :  "  Mine  was  the  case 
of  a  man  to  whom  had  been  given  the  imperfect  re- 
mains of  some  hundreds  of  skeletons  belonging  to 
twenty  sorts  of  animals.  It  was  necessary  that  each 
bone  should  find  itself  alongside  that  to  which  it  had 
been  connected.  It  was  almost  like  a  small  resurrec- 
tion, and  I  had  not  at  my  disposal  the  all-powerful 
trumpet;  but  I  did  have  the  unchangeable  laws  by 
which  living  beings  were  created  as  my  guide,  and  at 
the  voice  of  the  anatomist  each  bone  and  each  part  of 
a  bone  took  its  place." 

If  you  take  notice,  you  know  something  of  this 
yourself — that  animals  which  chew  the  cud,  like  cows, 
and  have  a  peculiar  kind  of  teeth,  also  have  cloven 
hoofs.  Darwin  has  carried  this  study  further  even 
than  Cuvier  did.  He  studied  all  the  different  parts 
of  animals  and  their  relations  to  one  another.  He  has 
made  some  very  curious  discoveries  in  regard  to  such 
relations,  for  example :  White  cats  with  blue  eyes  are 


134  The  Earth  in  Past  Ages. 

sure  to  be  deaf;  and  young  kittens,  so  long  as  their 
eyes  are  blue,  are  also  deaf.  Some  South  American 
horses,  instead  of  straight  hair,  have  curly  wool ;  and 
these  horses  have  mules'  hoofs.  Angora  goats,  when 
they  have  long,  curly  hair,  have  long  horns ;  while  the 
hornless  ones  are  found  with  short  hair.  A  great 
many  curious  things  of  this  kind  have  been  observed. 
You  can  see  that  in  finding  out  about  animals  from 
their  bones,  certain  of  these  relations  must  often  be 
of  great  assistance  where  all  of  the  bones  of  any  of 
the  animals  he  was  trying  to  understand,  or  "  restore," 
as  it  is  called,  had  not  been  discovered. 


CHAPTER  XIII. 
THE  DAWN  OF  LIFE. 

AFTER  the  terrible  storms  and  earthquakes  and  vol- 
canic fires  had  done  their  earliest  work  in  building  up 
the  world,  a  quiet  settled  down  upon  the  earth.  The 
hot  rains  that  had  for  so  long  been  pouring  down  into 
the  hot  seas  became  gentler.  The  heavy  clouds  which 
had  hung  like  a  pall  over  the  face  of  the  earth  some- 
times lifted.  A  watery  daylight  shone  faintly  over 
the  waste  and  desolate  seas,  and  showed  the  bare 
and  jagged  rocks  of  the  new-born  continents  and 
islands. 

Under  the  surface  of  the  still  water  of  the  seas  and 
the  lakes  faint  stirrings  of  life  began.  The  first  liv- 
ing things  were  very  simple  beings  —  little  more,  in- 
deed, than  formless  masses  of  jelly,  such  as  may  be 
found  on  sea-bottoms  nowadays.  Such  beings  might 
have  lived  by  millions,  and  died  and  left  no  sign,  as 
they  are  doing  at  the  bottom  of  the  Atlantic  Ocean 


136  The  Earth  in  Past  Ages. 

to-day,  as  they  would  naturally  be  easily  crushed  out 
of  shape,  destroyed,  and  washed  away. 

Some  of  them,  however,  vegetable  as  well  as  animal, 
have  horny  or  chalky  or  glassy  shells.  Though  the 
living  parts  quickly  disappear,  the  shells  last  for  a 
long,  long  time.  We  might  expect  to  find  traces  of 
such  shells  in  the  rocks  that  formed  the  ancient  sea- 
bottom  ;  and  so  wre  do  find  them  here  and  there,  but 
very  few  and  very  far  between. 

"No  history  is  able  to  write  its  own  beginning." 
All  the  earliest  histories  of  different  peoples  are  con- 
fused and  dim ;  this  is  true  even  of  America.  When 
we  go  back  to  its  real  beginning — long  before  the  peo- 
ple of  Europe  came  over  and  settled  it,  and  before  even 
the  Indians  they  found  here  were  living — mighty  na- 
tions occupied  the  land.  We  have  no  written  histories 
of  these  people,  but  we  know  they  lived  here,  because 
we  find  on  the  Western  plains  curious  mounds  which 
they  raised,  and  on  the  cliffs  in  the  mountain  countries 
still  farther  west  wonderful  dwellings  built  upon  and 
cut  into  the  rocks.  We  do  not  need  written  words  to 
tell  us  that  life  once  existed  there ;  the  cliff  dwellings 
tell  us  that  plainly  enough. 

Just  so  in  the  rocks  that  were  once  at  the  bottom 


The  Dawn  of  Life.  137 

of  these  old  seas  we  find  the  dwellings — the  shells— 
in  which  the  earliest  life  was  housed.  What  sort  of 
life  it  was  we  can  only  judge  by  studying  the  life  like 
it  which  exists  now,  and  by  guessing  out  the  secret 
slowly  as  our  knowledge  grows. 

A  great  deal  of  this  scientific  guessing  has  to  be 
done  in  searching  out  the  truths  of  nature.  I  want 
you  to  see  just  what  sort  of  guessing  it  is.  The  first 
trace  of  a  living  creature  found  in  the  lowest  rocks  is 
certainly  an  animal,  or  colony 
of  animals,  whose  shell  has 
been  enclosed  in  the  mud, 
which  has  hardened  over  it, 
and  preserved  it  for  millions 
of  years  (Fig.  47).  And  yet, 
in  spite  of  our  knowledge  of 

1  Fig.  47. — EOZOON  CANADENSE. 

this  fact,  we  guess  that  plants 

From  Lyell's  "Elements  of  Geol- 

were  created  before  animals.  ogy." 

Why? 

Because  from  a  careful  study  of  plant  life  we  find 
that  plants  have  a  power  possessed  by  nothing  else, 
the  power  of  feeding  on  minerals,  of  living  and  grow- 
ing with  no  other  thing  to  feed  upon  but  earth  and 
air  and  water.  Those  were  just  the  things  to  be  found 


138  The  Earth  in  Past  Ages. 

on  our  earth  at  first.  Animals  have  life  too,  but  they 
cannot  feed  upon  minerals  alone.  Besides  the  air  and 
the  water,  and  salt  and  some  other  minerals,  they  must 
have  as  food  something  that  has  been  alive — vegeta- 
ble or  animal  food. 

You  see,  then,  why  we  guess  that  plants  came  first : 
because,  as  the  earth  then  was,  the  food  for  plants  was 
there,  while,  till  the  plants  had  come,  no  food  for  ani- 
mals existed.  This  is  no  wild  and  foolish  guessing, 
but  a  sober  conclusion  reached  through  knowledge. 
I  have  been  so  very  particular  about  this  because 
many  people  who  are  ignorant  of  geology  —  that  is, 
the  science  of  earth-making — are  fond  of  speaking  of 
it  with  contempt,  calling  it  mere  guesswork ;  and  I 
want  you  to  see  just  what  sort  of  guesswork  it  is. 
"Without  this  kind  of  guessing  the  world  would  still  be 
in  darkness  on  most  subjects  worth  knowing.  The 
only  danger  in  the  matter  is  when  the  guesses  are 
insisted  upon  as  facts  proved  to  be  true. 

The  vegetable  life  in  the  sea-bottom  is  very  differ- 
ent from  anything  we  usually  see.  The  plants  there 
are  often  mere  lumps  of  greenish  jelly,  but  they  have 
the  power  that  belongs  only  to  vegetable  life,  of  trans- 
forming the  minerals,  earth,  and  air,  and  water,  into 


The  Dawn  of  Life.  139 

some  material  like  that  they  are  composed  of ;  that  is, 
they  live  and  grow,  feeding  on  minerals  alone.  Things 
that  are  alive,  high  or  low,  animal  or  vegetable,  show 
that  they  are  alive  by  doing  something,  and  show 
which  they  are  by  what  they  do.  Minerals  and  met- 
als never  do  anything ;  they  are  acted  upon  and 
changed,  but  they  have  no  power  to  work  changes  in 
other  things.  That  power  is  something  wonderful 
and  mysterious,  and  we  call  it  life.  All  things  into 
which  God  has  breathed  this  power  are  called  organic, 
because  they  have  organs  by  which  they  live  and  grow. 
The  rest  of  the  things  in  the  world  are  morganic,  not 
organic. 

The  vegetable  life  that  came  first  was  all  in  the  wa- 
ter, but  it  was  just  the  sort  of  food  necessary  for  the 
first  animals,  which  also  lived  in  the  water.  The  two 
lived  side  by  side;  you  could  not  tell  one  from  the 
other,  they  looked  so  much  and  seemed  so  much  alike. 
The  only  way  you  could  tell  was  to  wait  and  see  what 
each  would  do. 

After  a  while  these  simple  jelly-like  forms  were  fol- 
lowed by  a  higher  kind  of  vegetable  life.  Delicate 
sea -plants  floated  through  the  waters  (Fig.  48),  and 
were  imprisoned  in  the  rocks,  where  they  are  found 


140  The  Earth  in  Past  Ages. 

to-day.  Masses  of  sea -weed  growing  in  favorable 
spots  have  been  enclosed  in  solid  blocks  of  stone  (Tig. 
49),  besides  many  other  soft  and  delicate  water-plants. 


Fig.  48. — SEA-WEEDS  AND  SEA  ANIMALS. 
From  Hooker's  •'  Mineralogy  and  Geology." 

The  way  being  paved  for  them,  many  curious  ani- 
mals also  had  begun  to  fill  the  waters.  All  very  sim- 
ple, though  some  were  much  larger  than  anything  of 
their  kind  living  to-day.  Each  age  since  life  came 
upon  our  globe  seemed  to  belong  to  a  certain  class  of 
being,  beginning  with  the  lowest,  and  growing  higher 
and  higher.  This  time  might  almost  have  been  called 
the  reign  of  jelly.  As  higher  kinds  of  beings  came  in 
they  did  not  push  out  the  lower,  the  jelly-like  animals 
and  plants  existing  in  great  numbers  still,  so  that  the 


The  Dawn  of  Life. 


141 


whole  sea -bottoms  are  covered  with  them;  but  the 
lower  and  simpler  life  seemed  to  sink  into  less  impor- 
tance when  a  new  reign  began. 

The  most  singular  creature  in  the  old  seas,  which 
might  almost  be  called  the  king  of  the  jelly  kingdom, 


Fig.  49. — SILURIAN  SEA-WEED. 
From  Winchell's  "Sketches  of  Creation." 

was  a  queer  three -lobed  shell -fish.  It  is  known  to 
have  had  legs,  because  its  nearest  of  kin  living  now  is 
formed  in  somewhat  the  same  way  (Fig.  51). 

Beautiful  star-fish  (Fig.  50)  swam  through  the  waters 
of  these  seas ;  lovely  corals  (Fig.  52)  crowded  the  bot- 


142 


The  Earth  in  Past  Ages. 


toms,  and  slowly  grew 
towards  the  light;  tall 
and  graceful  stone-lilies 
shot  upward  through 
the  water ;  gigantic 
sponges  and  queer 
plant-like  creatures  call- 
ed grapholites  grew  in 
great  numbers  (Fig.  48). 

These,  though  in  many  respects  seeming  to  be  plants, 
are  really  animal  forms.  Shell-fish  too,  in  great  vari- 
ety, lived  and  died  in  those  old  days. 

The  climate,  judging  from  the  creatures  that  lived 


Fig.  50.— STAR-FISH. 
From  Lyell's  "Elements  of  Geology.' 


Fig.  51. — TRILOBITES. 
From  Lyell's  "  Elements  of  Geology." 


The  Dawn  of  Life.  143 

then,  must  have  been  rather  warm  all  over  the  world ; 
the  heat  from  the  earth  would  help  to  keep  the  waters 
warm,  and  the  clouds  of  mist  wrapped  the  earth  around 
like  a  blanket,  and  would  not  let  the  heat  all  escape. 


Fig.  52.— CORALS. 
From  Hooker's  "Mineralogy  aud  Geology." 

Though  the  waters  were  teeming  with  life,  the  land 
remained  desolate.  Bare  rocks  and  barren  sands  stood 
out  of  the  dark  waters  and  under  the  lowering  sky. 
Not  a  spear  of  grass,  not  a  bush,  nor  tree,  nor  flower 
relieved  the  barren,  lifeless  stretches,  but  the  time  was 


144  The  Earth  in  Past  Ages. 

drawing  near  when  the  earth  should  be  clothed  with 
beauty  as  with  a  garment. 

The  soft  and  formless  beings  that  filled  the  waters 
were  not  living  for  themselves  alone ;  they  were  also 
preparing  the  world  for  the  higher  and  nobler  life  that 
was  to  come. 

We  have  only  been  watching  the  dawning  of  life 
which  had  been  gently  stealing  upon  the  world,  but  it 
was  as  important  to  the  full  life  that  was  coming  as 
is  the  dawn  of  every  new  day  which  ushers  in  the  sun 
with  all  the  attendant  beauty  and  stir  of  a  full-pulsed 
life. 


CHAPTER  XIV. 
THE  REIGN  OF  FISHES. 

ABOUT  this  time  the  world  was  very  wonderful,  and 
filled  with  strange  inhabitants.  The  sun's  rays,  still 
struggling  through  clouds  of  mist  and  banks  of  fog, 
shone  upon  wide,  shallow  seas.  Here  and  there  the 
roll  of  the  waves  was  broken  by  bare,  jutting  rocks,  or 
by  low,  flat  mud-banks.  The  sun  baked  the  mud,  and 
it  dried  and  cracked  and  warped  up  in  the  heat,  till 
some  day  a  loud  rumbling  would  be  heard,  the  mud- 
bank  crumble  up  and  sink  beneath  the  water,  and  the 
waves  roll  on  unchecked  over  the  spot.  Somewhere 
else,  before  long,  another  mud-bank  would  arise,  bake 
in  the  heated  air,  crumble  away,  and  disappear. 

The  inhabitants  of  this  world  all  lived  in  the  water. 
They  were  the  flower-like  coral  animals  which  slowly, 
year  by  year,  built  up  circular  islands  from  the  beds 
of  the  shallow  seas,  or  lowly,  palpitating  jelly-fish, 
dragging  their  long  ribbon -like  arms  after  them,  or 
10 


146  The  Earth  in  Past  Ages. 

star-fish,  or  creatures  living  protected,  as  our  clams 
and  oysters  do,  between  two  hard  shells.  One  thing, 
and  it  is  the  commonest  kind  of  thing  in  our  world, 
was  not  to  be  found  then,  and  that  is  a  backbone. 

This  period  followed  the  dawn  of  life  upon  the 
earth ;  the  creatures  that  now  appeared  were  not 
only  larger,  but  a  higher  kind  of  being. 

You  know  very  well,  if  you  ever  noticed  at  all, 
when  you  were  carefully  taking  the  bones  out  of  a 
piece  of  shad  or  other  fish  before  putting  it  in  your 
mouth,  that  a  backbone  is  really  made  up  of  a  num- 
ber of  separate  bones  neatly  fitted  together,  to  which 
the  other  bones  are  attached.  These  separate  bones, 
making  up  the  backbone,  are  called  vertebrae.  The 
lower  forms  of  life — those  which  have  no  backbone- 
are  classed  together,  and  called  invertebrates ;  the 
higher  are  called  vertebrates. 

The  old  world  we  have  been  trying  to  picture  was 
only  our  world  before  it  was  "  grown  up."  Fire  and 
water  and  ice  had  not  yet  finished  their  part  in  the 
work  of  world-building ;  but  all  the  while  it  was  mak- 
ing ready  for  higher  kinds  of  beings,  and  slowly,  one 
by  one,  these  beings  came  into  existence.  There  are 
places  heie  and  there  in  our  world  nowadays  that  look 


The  Reign  of  Fishes.  147 

very  much  as  every  part  of  the  earth  must  have  looked 
then.  Hugh  Miller — the  poor  Scotch  boy  you  read 
about  in  Chapter  II. — has  studied  this  part  of  the 
world's  history  very  patiently  and  carefully.  He  says 
that,  looking  off  from  the  rocky,  barren  coast  of  the 
western  part  of  Scotland,  you  see  only  bare  rocks  cov- 
ered with  dismal  sea- weed,  clumps  of  it  growing  on 
the  rocks  that  are  washed  over  by  the  waves,  long 
floating  streamers  rising  and  falling  with  the  tide; 
shallow  sheets  of  water,  whose  beds  are  covered  with 
other  kinds  of  green  water-weeds  and  shells.  All  this, 
he  says,  is  very  much  what  any  part  of  the  earth  would 
have  shown  in  the  days  before  the  fishes  began  their 
reign. 

But  the  dawn  of  life  which  first  glimmered  in  these 
ancient  seas  did  not  go  out  in  darkness,  it  did  not  even 
stand  still,  but  grew  more  and  more  into  the  perfect 
day.  It  became  stronger  and  spread  wider,  filling  the 
seas  with  hundreds  of  new  forms  of  life,  and  thousands 
upon  thousands  more  of  the  old  forms  —  corals  and 
star-fish  and  shell-fish ;  and  then  came  the  creatures 
with  the  backbones,  and  the  reign  of  the  vertebrates 
had  begun.  Fish  are  the  lowest  of  the  vertebrates,  so 
they  came  first.  The  geologic  fish  were  like,  and  yet 


148 


The  Earth  in  Past  Ages. 


unlike,  the  fish  we  now  find.  Curious  creatures,  some 
of  them,  wearing,  like  the  knights  of  old,  heavy  hel- 
mets, or  even  a  complete  suit  of  armor,  to  protect  them 

against  other  mon- 
strous armed  fish,  with 
which  they  lived  in  per- 
petual warfare. 

The  wing-fish  (Fig. 
53)  wore  on  its  head  a 
heavy  helmet,  with  two 
holes  for  the  eyes ;  the 
body  was  covered  with 
a  coat  of  mail  made  of 
strong  plates,  and  the 
tail  was  protected  with 
a  flexible  armor  of  bony 
scales.  The  tail,  which  could  scull  the  animal  along  if 
necessary,  also  served  as  a  rudder  if  he  decided  to  use 
his  paddles  to  carry  him  through  the  water.  These 
were  two  long  arms  that  projected  from  each  side  of 
his  head. 

Three  kinds  of  mailed  fish  are  given  in  Figure  54. 
No.  1  has  the  upper  part  of  its  body  incased  in  armor; 
No.  2  has  plates  of  bone  protecting  its  whole  body ; 


Fig.  58. — WING-FISH. 
From  Lyell's  "Elements  of  Geology." 


The  Reign  of  Fishes. 


149 


and  No.  3  wears  a  queer  helmet,  made  of  a  single  bone. 
Some  of  the  singular  scales  out  of  which  the  armor  is 
made  are  given  in  Figure  55.  One  of  the  great  mailed 


FIG.  54. — MAILED  FISHES. 
From  Hooker's  "Mineralogy  and  Geology." 

fish  of  that  time  was  as  large  as  an  alligator ;  the  hel- 
met it  wore  would  cover  the  front  part  of  an  ele- 
phant's skull,  and  was  thick  enough  to  turn  aside  a 
musket-ball.  Though  this  was  truly  a  fish,  it  had  the 
jaws  and  teeth  of  an  alligator. 

The  rocks  belonging  to  this  time  are  called  the  old 


150 


The  Earth  in  Past  Ages. 


red  sandstone.  Perhaps  it  will  interest  you  to  know 
(as  I  remember  it  interested  me  when  I  first  found  it 
out)  that  the  brown  stone  of  which  so  many  houses 
and  churches  are  built  in  this  country,  particularly  in 
New  York  City,  is  old  red  sandstone.  It  is  wonderful 
to  think  that  many  of  the  blocks  of  stone  which  form, 


Fig.  55. — SCALES. 
From  Hooker's  "  Mineralogy  aud  Geology.' 


perhaps,  our  own  homes  hold  within  them  curious  fish 
and  shells  that  lived  in  these  old  seas.  Hugh  Miller 
tells  us  of  what  he  found  among  the  rocks  of  that  day, 
which  showed  how  full  the  sea  was  of  fish,  and  how 


The  Reign  of  Fishes. 


151 


Fig.  56. — UNILOBED  TAIL. 

From  Hooker's  "Mineralogy  and  Geol- 
ogy." 


Fig.  57. — BILOBED  TAIL. 

From  Hooker's  "Mineralogy 
and  Geology." 


suddenly  sometimes  whole  armies  of  them  were  over- 
Avhelmed  and  killed  by  the  sudden  upheavings  of  the 
earth's  thin  crust.     He  says  that  he  found  what  he 
calls    "  one   of    those    plat- 
forms of  violent  death  for 
which  the  old  red  sandstone 
is  so  remarkable :"  the  layer 
of   rock   laid    open   by  his 
hammer  was  covered  with 
the  remains  of  a  whole  fleet 
of  mailed  fish,  some  of  them 
still  twisted  and  contorted 
as  in  their  dying  agony. 

Though  fish  were  the 
reigning  kind  of  life  in  this 
age,  there  were  other  creat-  Fig.  58  —STONE-LILIES. 


152 


The  Earth  in  Past  Ages. 


Fig.  69. — PSILOPHYTON. 


ures  still  more  beauti- 
ful and  curious.  Along 
the  shallows  near  the 
shores  of  the  sea  grew 
great  gardens  of  stone- 
lilies.  These  are  won- 
derful creatures  —  an- 
imal, not  vegetable ; 
they  are  cousins  of  the 
star-fishes,  but  they  are 
shaped  something  like 
a  flower,  and  grow 
upon  stems  (Fig.  58). 

The  land,  too,  began 
to  show  signs  of  life ; 
the  sea -weeds  and  a 
few  mosses  which  had 
been  all  the  earth 
brought  forth  gave 
place  to  singular 
plants,  which  grew  to 
the  size  of  trees.  Fig- 
ure 59  shows  a  sort  of 
club-moss,  which  looks 


The  Reign  of  Fishes.  153 

more  as  if  it  had  been  drawn  upon  a  slate  by  a  very 
young  artist  than  something  that  had  ever  grown 
and  borne  fruit  as  curious  as  itself.  Enormous  reeds 
shot  up  through  the  marshy  soil,  sending  out  feathery 
shoots  that  made  them  look  like  giant  trees.  Forests 
of  slender  stems  bearing  star-shaped  drooping  leaves 
covered  the  mud-banks,  and  mighty  ferns  lifted  their 
fronds  to  the  height  of  many  feet. 

There  were  a  few  trees  too,  whose  rings,  which  can 
still  be  counted,  tell  that  they  were  a  hundred  or  more 
years  old,  and  give  us  a  hint  that  in  those  old  days  there 
were  summer  and  winter,  seed-time  and  harvest,  as  well 
as  now.  You  know  that  the  rings  which  show  in  a 
stump  of  wood  show  the  age  of  the  tree.  Each  ring  is 
made  up  of  a  layer  of  loose,  soft  wood,  and  one  of  hard 
wood  next  it.  The  loose,  soft  wood  grows  in  spring  and 
summer,  and  the  close,  hard  wood  in  fall  and  winter. 
From  this  we  can  tell  that  each  year  had  a  season  of 
growth — summer — and  a  season  of  rest — winter — and 
just  how  many  years  the  tree  lived. 

The  age  that  is  to  follow  is  one  full  of  marvels,  and 
here  and  there  in  the  time  we  are  speaking  of  we 
catch  a  hint  of  the  coming  beauty  and  glory  breaking 
through  the  desolation  that  had  so  long  held  sway. 


CHAPTER  XV. 

THE  REIGN  OF  PLANTS. 

DOWN  deep  in  the  earth,  hundreds  of  feet  below 
the  surface,  may  be  found  strange  cities,  roofed  over, 
walled  in,  and  pillared  with  what  looks  like  jet-black 
stone.  No  light  reaches  the  narrow  streets,  except 
here  and  there  where  a  flaring  lamp  stuck  into  a  sock- 
et in  the  wall  makes  a  circle  of  brightness  around  it, 
or  a  tiny  flame,  imprisoned  in  a  wire  cage,  and  worn 
in  the  front  of  his  cap  by  each  of  the  dwellers  in  this 
underground  world,  sends  out  a  slender  flame  to  light 
him  on  his  way. 

This  curious  place  is  a  coal-mine,  which  has  been 
slowly  dug  out  by  men  who  toiled  there  day  after  day 
and  year  after  year,  away  from  the  light  of  the  sun 
and  God's  beautiful  green  earth. 

I  want  you  to  go  back  with  me,  in  imagination,  to 
the  times  when  the  coal  was  making.'  We  must  go 
back  more  years  than  we  can  even  think  of  to  do  this. 


The  Reign  of  Plants.  155 

It  was  after  the  reign  of  the  fishes ;  the  land  then 
existing  was  only  low  mud-banks  and  barren  rocks, 
where  a  few  plants  and  trees  were  growing.  Most  of 
the  globe  was  covered  with  water,  ceaselessly  beating 
upon  the  desolate  shores. 

A  death-like  silence  hung  over  the  dreary  land  and 
sullen  waters.  No  insect's  hum  or  bird's  song  broke 
the  stillness  of  the  air.  The  sounds  that  might  have 
been  heard,  if  there  had  been  an  ear  that  could  listen, 
were  sounds  of  destruction  and  death  rather  than 
sounds  of  life.  The  heavy  muttering  of  the  storm, 
the  sudden  claps  of  thunder  echoing  through  the  hol- 
low air,  the  crash  of  earthquake  and  volcano,  and  then 
silence  again,  marked  by  the  monotonous  roll  of  the 
waves,  as  the  silence  of  night  is  marked  by  the  regu- 
lar tick  of  a  clock. 

It  almost  seemed  as  if  /  the  earth,  in  spite  of  the 
heat,  had  not  yet  been  released  from  the  death -like 
spell  of  winter.  But  at  last  a  new  life  was  beginning 
to  wake.  Almost  as  spring  comes  to  us  each  year 
this  awakening  came  to  the  bare  and  desert  land. 
Cannot  you  look  back  upon  last  winter  and  remember 
how  long  it  seemed? — how  you  waited  and  watched 
for  the  spring  so  eagerly  and  impatiently  that  it 


156  The  Earth  in  Past  Ages. 

seemed  as  though  it  would  never  come?  At  last, 
when  you  had  almost  begun  to  despair,  there  came  a 
few  soft,  warm  days,  and  the  miracle  of  nature  was 
wrought.  The  whole  air  was  full  of  the  whispers  of 
the  coming  leaves,  murmuring  their  gladness  as  they 
burst  from  their  dark  prison-houses  in  the  rough 
boughs,  and  pushed  their  way  out  into  the  air  and 
sunshine. 

Now  that  the  spring  had  come  to  the  world,  after 
millions  of  years  of  waiting,  it  brought  a  wonderful 
and  brilliant  life.  The  excessive  heat  and  moisture 
together  made  of  the  whole  land  one  great  green- 
house. The  plants  grew  to  a  gigantic  size.  The 
swampy  ground  brought  forth  huge  reeds  that  reared 
themselves  forty  or  fifty  feet  high,  and  were  clothed 
with  masses  of  feathery  leaves.  Ferns  shot  up  tall 
trunks  crowned  with  foliage  like  palms.  Singular 
trees,  unlike  any  living  now  upon  the  earth,  whose 
trunks  looked  like  carved  columns  of  wood,  filled  the 
forest,  and  must  have  given  it  a  most  peculiar  look. 

In  this  ideal  landscape  the  trees  and  plants  that  are 
known  to  have  made  up  the  coal  forests  are  shown. 
In  the  water  on  the  left  of  the  scene  are  two  things 
peeping  up  that  look  like  asparagus  tips.  These  are 


The  Reign  of  Plants. 


159 


the  growing  ends  of  the  reeds  that  are  going  to  make 
great  trees.  In  the  middle  and  to  the  right  are  some 
singular  round  balls  with  long  fringed  arms  lying  out 
on  the  water.  These  for  a  long  time  were  a  great 
puzzle  to  geologists,  till  in  some  of  the  coal-beds  they 


Fig.  61. — COAL  FERNS. 
From  Winchell's  "Sketches  of  Creation." 

were  found  to  be  the  roots  of  the  carven  stems  near 
them.  The  marking  on  the  stems  was  also  found  to 
be  scars  left  by  leaves  which  had  fallen  off ;  but  the 
plants  that  were  most  common  and  grew  most  freely 
were  ferns,  both  tree  and  creeping  ferns.  These  plants 
were  all  found  in  the  swamps ;  at  the  same  time  on 


160  The  Earth  in  Past  Ages. 

the  rocky  lands  a  few  evergreens  had  sprung  up, 
which  were  sometimes  carried  down  in  the  freshets 
and  packed  among  the  living  plants  of  the  swamps. 

It  seems  a  wonderful  leap  to  make  from  such  a 
dense  living  forest  as  this  to  a  seam  of  solid  coal,  ly- 
ing between  layers  of  stone,  hundreds  of  feet  under- 
ground, and  so  it  would  be  if  we  tried  to  take  it  in 
one  jump.  But  we  are  able  to  trace  the  change  step 
by  step  from  wood  to  coal  almost  as  perfectly  as  we 
can  the  wood  that  is  stacked,  and  covered  in  from  the 
air,  and  slowly  heated  till  it  turns  into  charcoal,  in 
the  charcoal-burner's  pits. 

Do  you  remember  anything  about  the  peat-bogs  we 
were  examining  in  Chapter  VII. — how  the  leaves  and 
stems  of  plants,  and  even  stumps  and  logs  of  wood, 
sunk  in  the  swampy  waters,  instead  of  turning  to  dust 
and  blowing  away,  as  they  would  have  done  in  the 
air,  were  packed  down  and  gradually  changed  into  a 
black,  pasty  mass,  and  that  this  mass  when  dried 
would  burn  ?  Well,  peat  is  the  first  step  that  wood 
takes  in  its  change  into  coal. 

Coal  is  nothing  but  wood — leaves,  stems,  roots,  and 
trunks — which  under  water,  and  by  means  of  heat  and 
pressure,  has  slowly  changed  its  form.  A  coal  fire  is, 


Fig.  62. — TREE-TRUNKS  FOUND  IN  A  MINE. 
From  Winchell's  "Sketches  of  Creation." 


The  Reign  of  Plants.  163 

after  all,  made  from  wood,  but  wood  that  grew  mill- 
ions of  years  ago,  and  was  packed  away  and  kept  all 
that  time  underground,  while  a  wood  fire  comes  from 
last  year's  forest  that  was  cut  and  for  a  few  months 
perhaps  stored  away  to  dry. 

We  can  find  in  different  parts  of  the  world  fuel  in 
all  its  various  stages  of  change  from  wood,  through 
peat  and  brown  coal  and  soft  coal  of  various  kinds,  up 
to  hard  coal.  Two  other  things  that  we  do  not  think 
of  as  coal  form  links  in  this  chain  of  change.  Jet,  out 
of  which  jewellery  is  made,  is  one  form  of  soft  coal, 
and  graphite,  that  makes  the  best  lead  for  lead-pencils, 
is  the  hardest  of  the  hard  coals. 

A  piece  of  common  coal  ground  down  into  a  thin 
slice  shows  under  the  magnifying-glass  just  the  sort 
of  cells  that  a  piece  of  wood  cut  thin  and  even  will 
show.  Perfect  leaves  are  often  found  in  coal,  with 
every  vein  distinct ;  and  in  some  coal-mines  great  tree- 
trunks  of  solid  coal,  embedded  in  coal  as  solid,  have 
been  found  (Fig.  63). 

You  remember  the  sudden  changes  in  this  old  world 
were  something  like  what  happen  now,  only  more  vi- 
olent and  more  swift.  The  coal  swamps  lay  usually 
near  river  -  mouths.  Besides  the  leaves  and  fallen 


164:  The  Earth  in  Past  Ages. 

trunks  from  the  forest  where  they  grew,  the  river  in 
its  uprising  would  carry  down  masses  of  logs  and  up- 
rooted trees,  and  pack  them  in  among  the  living- 
plants,  and  over  all  would  settle  loads  of  river  mud 
and  sand  brought  down  by  the  freshet.  Something 
like  this  is  going  on  at  the  mouth  of  the  Mississippi 
and  other  rivers  now,  and  peat-bogs  are  forming  there 
as  the  coal-beds  began  to  form  so  long  ago. 

Coal  seams  are  large,  flat  layers  of  coal  pressed  be- 
tween layers  of  various  kinds  of  rock.  Usually  there 
are  many  layers  of  coal  with  layers  of  rock  between, 
like  a  natural  jelly-cake,  the  jelly  being  the  coal,  and 
the  cake  the  thick  rock  between.  Each  layer  of  coal 
represents  a  buried  forest,  and  the  layer  of  stone  just 
under  it  is  crowded  with  the  roots  and  stumps  stand- 
ing just  as  they  grew  millions  of  years  ago.  In 
Wales,  in  one  place,  there  are  one  hundred  layers  of 
coal,  with  rocks  between,  one  on  top  of  the  other,  for 
over  two  miles  deep. 

Though  plants  reigned  in  the  coal  -  measures,  the 
waters  were  not  empty  of  animal  life :  great  fish 
swam  about  in  the  waters,  beautiful  corals  clustered 
on  the  rocks  near  the  sea  surface,  star-fish  and  stone- 
lilies,  shell-fish  and  lobster-like  creatures,  dwelt  in  the 


The  Reign  of  Plants. 


165 


Fig.  63. — SLAB  OF  SANDSTONE  SHOWING  FOOTPRINTS  OF  SAURIANS. 
Prom  Lyell's  "Elements  of  Geology." 

sea.  A  few  insects  had  begun  to  flit  about  over  the 
surface  of  the  water,  and  enormous  lizards  made  their 
appearance.  Clumsy  footprints  on  the  sandstones 
(Fig.  63)  show  where  they  have  lived  and  swarmed, 


166  The  Earth  in  Past  Ages. 

and  singular  skeletons  leave  in  the  rocks  a  record  of 
their  deaths.  A  new  and  higher  life  had  begun  in  the 
animal  world  while  the  coal  forests  were  growing  and 
perishing  and  being  packed  away  for  future  use. 

After  the  end  of  this  period  the  earth,  with  its  great 
beds  of  forest  and  forming  coal,  suffered  terrible  con- 
vulsion. Again  the  crust  was  thrown  into  wrinkles. 
The  mountains  of  our  Eastern  States  were  thrown  up 
at  that  time,  and  then  the  water  began  wearing  them 
down.  The  animals  and  plants  of  the  coal  period  be- 
gan slowly  dying  out.  It  was  like  the  twilight  of  the 
day  that  had  dawned  so  long  ago ;  but  it  came  before 
a  time  of  comparative  rest,  and  the  dawn  of  a  new 
day. 


CHAPTER  XVI. 

STRIKING 


THE  expression  "  striking  oil  "  is  such  a  common, 
every-day  phrase  that  we  hardly  stop  to  remember 
what  it  really  means,  and  yet  thirty  years  ago  such  a 
term  was  never  used,  for  the  very  fact  that  gave  rise 
to  it  did  not  exist. 

A  hundred  years  or  so  ago  a  curious  sight  might 
have  been  seen  in  the  Indians'  country  of  western 
Pennsylvania.  Early  in  the  morning  one  of  the 
squaws  would  carry  a  dirty  blanket  down  to  the 
borders  of  the  stream.  A  natural  conclusion  would 
be  that  she  was  about  to  give  her  blanket  a  much- 
needed  washing.  But  no  ;  instead  of  dipping  the 
blanket  in  the  water  and  rubbing  and  squeezing  and 
wringing  it,  she  merely  flings  it  out  on  the  surface  of 
the  stream,  and  when  it  becomes  soaked  draws  it  tow- 
ards her  and  begins  carefully  squeezing  out  the  liquid 
that  it  has  caught  in  its  meshes  into  a  gourd.  The 


168  The  Earth  in  Past  Ages. 

observer  begins  to  catch  the  idea.  It  is  not  a  clean 
blanket  that  she  wants,  but  the  disagreeable,  ill-smell- 
ing, greasy  scum  that  floats  upon  the  surface  of  the 
water. 

In  this  simple  manner  and  by  these  queer  means 
the  Indians  of  that  time  collected  oil,  not  to  give  them 
light,  but  to  be  used  as  a  liniment  to  rub  their  poor 
joints  when  swollen  with  rheumatism.  This  was  the 
old  savage  way  of  "  striking  oil ;"  for  this  oil  gathered 
was  petroleum,  which  is  now  so  commonly  known  as 
kerosene,  but  was  then  called  "  Seneca  oil,"  and  used 
only  as  a  medicine. 

A  certain  Colonel  Drake,  who  had  a  farm  in  that 
part  of  the  country,  came  to  the  conclusion  that  some- 
where in  the  earth  was  to  be  found  a  reservoir  of  oil, 
which  he  could  reach  by  digging  for  it.  He  believed 

J  oo       O 

that  the  oil  which  oozed  out  of  the  rock  and  made  a 
greasy  scum  on  the  Oil  Creek  waters  came  from  some- 
where, and  that  somewhere  he  meant  to  discover.  His 
neighbors  amused  themselves  by  laughing  at  him  and 
joking  him,  much  as  Noah's  neighbors  did  when  he 
was  building  the  ark.  Their  tune  was  changed,  how- 
ever, when  in  the  summer  of  1859  Colonel  Drake 
"struck  oil."  In  the  course  of  four  months  Drake's 


"Sfrikwg  OiV  169 

well  had  poured  forth  two  thousand  barrels  of  oil 
Then  the  nation  took  the  oil  fever.  Speculators  rush- 
ed in,  new  wells  were  dug,  and  the  once  desolate 
fields  bristled  with  derricks. 

Before  Drake's  well  was  dug,  manufactories  were 
in  existence  in  which  oil  was  distilled  out  of  coal,  and 
called  coal -oil.  Petroleum  was  found  to  be  so  like 
this  substance  that  it  too  is  often  called  coal-oil,  and 
supposed  to  be  distilled  in  the  great  workshop  of 
nature  out  of  coal.  But  that  idea  is  incorrect.  It  is 
not  made  out  of  coal,  but  it  is  closely  connected  with 
coal  in  this  way,  that  both  coal  and  petroleum  are 
made  from  the  plant  life  of  the  past,  which  in  the 
course  of  ages  has  been  changed  into  these  two  sub- 
stances. If  coal -oil  were  made  out  of  coal,  it  would 
be  found  near  the  great  coal-beds.  This,  however,  is 
not  always,  not  even  usually,  the  case. 

We  have  seen  how  the  coal-beds  were  formed  by 
the  great  swamp  forests,  which,  under  fresh -water 
and  by  means  of  great  heat  and  pressure,  were  turned 
into  coal.  Oil,  it  is  thought,  is  formed  by  the  softer 
plants,  sea -weed  and  water-plants,  which  have  been, 
under  salt-water  and  at  a  lesser  heat,  distilled  beneath 
the  surface  of  the  earth.  The  oil  being  formed  in  the 


170  The  Earth  in  Past  Ages. 

water,  of  course  floated  on  the  top.  Sometimes  it 
soaked  into  porous  sandstone,  sometimes  it  ran  into 
holes  and  fissures  of  the  rocks.  Usually  it  is  found 
associated  with  the  salt-Avater  under  which  it  was 
gradually  formed. 

I  have  said  that  oil  is  distilled  out  of  plants ;  it  is 
also  distilled  in  much  the  same  way  from  the  animal 
life  of  the  past ;  bat  we  probably  owe  most  of  what 
is  sold  to  a  distillation  of  plants.  The  rocks  of  many 
periods,  besides  that  when  plants  grew  in  such  enor- 
mous quantities,  are  full  of  oil.  In  the  coal-beds,  you 
remember,  we  found  every  kind  of  coal  showing  the 
gradual  change  of  vegetable  matter  into  coal — from 
peat  through  soft  coal  to  hard  coaL  In  the  same  way 
petroleum  is  found  in  all  the  different  forms  it  takes 
on  in  its  change  —  light  oil,  heavy  oil,  bitumen,  and 
last,  it  is  thought  by  some,  diamond.  If  a  great  mass 
of  vegetable  matter  is  heaped  up  and  left,  and  after  a 
while  examined,  in  the  middle  of  it  is  found  an  oily, 
tarry  substance,  like  one  of  the  forms  of  petroleum — 
bitumen. 

"With  the  oil  and  the  salt-water  in  the  underground 
pools  there  is  found  a  quantity  of  gas  formed  from 
the  petroleum.  And  it  is  this  gas,  which  is  very  much 


"  Striking  Oil." 


171 


squeezed  up,  that  makes  the  oil  spout  up  when  a  bor- 
ing reaches  the  reservoir.  When  water  and  oil  and 
gas  exist  together  in  the  same  crevice  of  the  rock,  the 
water,  being  heaviest,  will  lie  at  the  bottom ;  on  top 
of  that  will  be  the  oil, 
and  above  both  of  them 
the  squeezed-up  gas  (Fig. 
64). 

Now  you  can  see  that 
if  a  well  is  dug  at  A,  the 
crowded-up  gas  will  force 

Up  water  in  trying  to  get      FiS-  64.— OIL  POOL  UNDER  THE  EAKTH. 

room  for   itself.      After    A>  water  well;  B' oil  wel1 ;  c' gas  well; 

D,  surface  ofthe  earth. 

the  water  has  all  come 

up,  if  the  gas  is  still  very  much  compressed,  the  oil, 
which  has  run  down  to  B  to  take  the  place  of  the 
water,  will  follow  the  flow  of  water.  If  the  power 
of  the  expanding  gas  has  gone,  the  oil  must  then  be 
pumped  up.  If,  however,  the  well  has  been  dug  at 
0,  gas  comes  up,  and  oil  must  be  pumped  up  when 
the  gas  has  all  escaped. 

Natural  gas  is  used  to  a  great  extent  to  light  and  in 
part  to  heat  great  cities  in  the  coal  and  oil  districts. 
It  seems  as  though  the  supply  must  soon  give  out,  but 


172  The  Earth  in  Past  Ages. 

as  a  matter  of  fact  it  seems  to  be  nearly  undiminished 
in  places  where  the  wells  have  been  blowing  off  gas 
for  nine  years.  And  if  it  should  give  out,  the  pipes 
being  all  laid,  it  is  possible  to  make  a  kind  of  cheap 
gas  at  the  mines  which  can  be  carried  and  used  as  the 
natural  gas  has  been. 

The  oil  is  certainly  failing  in  the  old  fields.  New 
fields  may  of  course  be  found,  and  probably  will ;  for 
the  oil  that  has  been  burned  all  over  the  world  until  a 
short  time  ago  came  mainly  from  a  strip  of  land  only 
one  hundred  and  fifty  miles  long,  and  from  two  to 
twenty  miles  wide.  But  of  late  years  there  has  been 
a  wonderful  discovery  of  oil  in  Russia,  where  wells 
have  spouted  the  incredible  amount  of  fifty  thousand 
barrels  a  day. 

The  great  works  that  used  to  distil  coal -oil  have 
been  turned  into  refineries  of  petroleum  (Fig.  65). 
After  the  kerosene  has  been  made,  a  thick,  tarry,  dis- 
agreeable stuff  is  left.  This  looks  like  the  most  hope- 
less sort  of  material  for  any  use,  but  out  of  it  are 
made  our  modern  "  wax"  candles, "  wax"  matches,  and 
even  some  sorts  of  candy  and  chewing-gum.  Another 
of  the  materials  left  when  the  kerosene  is  taken  out 
is  made  into  beautiful  dyes — colors  that  were  never 


Hit'""' 


,  I 


Fig.  65. — OIL  REFINERY,  SHOWING  TANK  CARS. 


"Striking  Oil^  175 

seen  in  old  times.  Unfortunately  these  colors  do  not 
hold  like  the  simpler  old-fashioned  dyes,  but  often  fade 
out,  or,  what  is  worse,  fade  into  very  ugly  tints. 

Much  of  the  oil  is  brought  from  the  region  where  it 
is  found  in  curious  tank  cars,  but  some  of  it  is  pumped 
through  pipes  three  hundred  miles  long,  from  the 
mines  to  the  refineries.  Beside  the  track  of  the  Cen- 
tral Railroad  of  New  Jersey  such  a  pipe  runs.  If  you 
ever  chance  to  go  over  that  road  to  Long  Branch  or 
Philadelphia,  or  to  some  Jersey  town  near  New  York, 
notice  this  pipe,  and  you  may  hear  the  oil  from  three 
hundred  miles  away  give  a  thud,  thud,  as  it  is  pumped 
into  the  reservoirs  at  Bayonne.  If  you  look  to  the 
eastward,  about  six  miles  below  Jersey  City  on  this 
road,  you  will  see  a  branch  track  curving  off  to  New 
York  Bay,  where  it  ends  in  a  forest  of  masts  and  fac- 
tories and  great  oil  tanks.  Many  a  time  you  may  see 
from  New  York  the  whole  heavens  ablaze  with  the 
fire  from  a  tank  that  has  been  struck  by  lightning  or 
has  caught  on  fire  some  other  way. 

A  still  more  wonderful  sight,  however,  is  to  see  a 
natural  oil  well  ablaze.  One  of  these  wells  at  Cherry 
Grove,  Pennsylvania,  in  the  summer  of  1882,  was 
sending  out  oil  at  the  rate  of  a  thousand  barrels  a 


176 


The  Earth  in  Past  Ages. 


day.  By  some  accident  it 
took  fire,  and  for  four  days 
and  nights  it  shot  up  into 
the  air  a  blazing  fountain, 
breaking  into  millions  of 
fiery  drops,  the  great  col- 
umn of  fire  swept  here 
and  there  by  the  passing 
winds.  The  fire  at  last 
was  quenched  by  shoot- 


Fig.  66. — A  FIELD  OF  DERRICKS. — EFFECT  OF  A  TORPEDO. 


"  Striking  Oil?'  177 

ing  off  with  a  cannon-ball  the  top  of  the  tube  out  of 
which  the  oil  was  spouting,  and  plugging  the  pipe 
below  the  blaze ;  but  some  of  these  wells  have  gone 
on  burning  till  all  the  oil  which  they  contained  has 
been  consumed. 
12 


CHAPTER  XVII. 
SALT. 

IN  the  Holy  Land  there  is  a  great  cleft  which  runs 
north  and  south,  and  ends  near  the  southern  part  of 
the  country.  Just  before  the  end  it  dips -deep  into  the 
earth,  more  than  a  mile  lower  than  the  level  of  the 
Mediterranean  Sea,  not  far  away.  Through  this  cleft 
flows  the  river  Jordan,  and  the  deep  gouge  into  the 
crust  of  the  earth  is  the  bottom  of  the  Dead  Sea.  This 
sea,  called  in  the  Bible  the  Salt  Sea,  is  one  of  the  most 
curious  bodies  of  water  on  the  face  of  our  earth.  If 
you  came  upon  it  in  your  travels  it  would  not  seem  so 
wonderful.  Under  the  bright  sun  of  Syria  you  would 
see  a  beautiful  sheet  of  blue  water  rippling  under  the 
breath  of  the  breeze,  bounded  on  either  side  by  bare, 
rugged  mountains,  with  scarcely  a  blade  of  grass  or 
tree  to  break  the  solitary,  barren  grandeur.  It  is  not 
horrible  and  greasy  to  the  look,  nor  disgusting  to  the 
smell,  as  many  old  writers  used  to  say — though  the 


Salt.  179 

shores  are  covered  with  a  brown,  pitchy  substance 
called  asphaltum,  and  great  masses  of  salt  and  sul- 
phur and  gypsum,  or  plaster  of  Paris. 

The  water  is  so  heavy  with  these  substances  that  a 
man  can  scarcely  sink  in  it,  but  when  he  tries  to  swim 
will  find  himself  almost  out  of  the  water,  and  his  feet 
kicking  in  the  air.  A  curious  old  writer,  who  visited 
the  Dead  Sea  before  Columbus  discovered  America — - 
in  fact,  more  than  four  hundred  years  ago — says,  "  It 
is  called  the  Dead  Sea  because  it  does  not  run,  but  is 
ever  motionless.  .  .  .  And  you  shall  understand  that 
the  river  Jordan  runs  into  the  Dead  Sea,  and  there  it 
dies,  for  it  runs  no  farther." 

In  this  sentence  he  tells  us  the  secret  of  the  sea. 
The  river  Jordan  does  run  into  the  salty  lake,  hemmed 
in  by  high  mountains  on  both  sides,  but  there  is  no 
way  for  the  water  to  get  out. 

You  know  when  water  is  put  in  a  shallow  vessel  it 
will  dry  up ;  that  is,  it  will  pass  into  the  air  in  an  in- 
visible steam,  or  vapor,  and  the  vessel  will  be  left  dry. 
If  you  take  some  water  in  which  a  great  deal  of  salt 
has  been  melted  and  let  it  dry  in  the  pan,  the  water 
will  dry  away,  leaving  the  salt  behind.  Suppose  every 
day  from  your  pan  of  salt-water  ten  spoonfuls  of  water 


180  The  Earth  in  Past  Ages. 

dried  away,  and  you  each  day  put  nine  spoonfuls  of 
fresh-water  into  it,  there  would  be  at  the  end  of  each 
day  a  little  less  water  in  the  pan,  and  it  would  be  a 
little  saltier  to  the  taste.  Now,  this  is  just  what  hap- 
pened to  the  Dead  Sea.  In  the  first  place,  the  sea  was 
probably  an  arm  of  the  Mediterranean,  which  was  cut 
off  from  it  by  the  lifting  up  of  the  land  between. 
This  salt  lake  would  soon  have  dried  up,  leaving  a 
flat  cake  of  salt  where  its  bottom  had  been ;  but  the 
river  Jordan  pours  into  it  "  and  dies,"  as  old  Sir  John 
says ;  but  in  dying  it  leaves  in  the  water  of  the  sea 
all  the  dissolved  earth  and  salt  and  other  things  it  had 
brought  down  in  its  current.  More  water  dries  out 
of  the  sea  each  day  than  the  Jordan  and  other  rivers 
bring  to  it ;  so  the  sea  for  long  ages  has  been  slowly 
shrinking  and  growing  saltier.  Along  the  old  sea 
margins  there  are  cakes  and  blocks  of  salt,  as  well  as 
asphalt  and  sulphur,  left  by  the  retiring  water ;  and 
at  the  bottom  of  the  sea  crystals  are  forming  and  set- 
tling down  from  the  intensely  bitter  salty  water. 

It  has  been  long  believed  that  the  Dead  Sea  covers 
the  cities  of  Sodom  and  Gomorrah,  but  that  is  a  mere 
guess.  That  the  cities  were  to  the  north  of  the  sea  is 
believed  by  people  who  have  studied  it  very  carefully, 


Salt.  181 

and  the  "  slime-pits  "  mentioned  in  the  Bible  were  pit* 
of  asphaltum  or  bitumen.  You  remember  that  I  tolo( 
you  in  the  chapter  on  oil  that  it  was  distilled  from 
vegetable  matter  under  salt -water.  This  asphalt  is 
only  one  of  the  harder  forms  of  oil,  and  here  we  find 
it  close  to  the  beds  of  salt. 

There  are  other  salt  lakes  in  the  world  something 
like  the  Dead  Sea,  but  none  that  are  so  curious  or  in- 
teresting. The  Caspian  Sea  is  a  sea  without  an  out- 
let ;  but  from  what  we  can  find  about  it  by  studying 
its  shores,  it  may  never  have  been  a  part  of  the  great 
ocean,  but  formed  and  made  salty  by  the  drying  up 
of  river-water  age  after  age,  leaving  the  settlings  to 
accumulate  till  the  water  of  the  Caspian  is  salty.  It 
is  plain  to  be  seen  that  the  Caspian  has  shrunk  a  great 
deal  owing  to  the  same  fact  that  has  caused  the  shrink- 
age of  the  Dead  Sea,  that  more  water  is  lost  by  drying 
than  is  gained  by  the  river's  tribute.  Still,  with  all  this 
loss  of  water,  it  is  not  so  salty  as  the  Mediterranean. 
This  is  one  of  the  reasons  it  is  not  thought  to  have  been 
an  arm  of  the  sea  cut  off,  though  it  is  not  quite  certain. 

Great  Salt  Lake,  where  the  Mormons  live,  is  a  sea 
like  the  Caspian,  mainly  made  by  the  rivers  that  emp- 
ty into  it  and  pass  away  in  vapor.  Ages  ago  Lake 


182  The  Earth  in  Past  Ages. 

Champlain  was  part  of  the  sea,  and  the  waters  were 
salt;  but  the  fresh- water  rivers  running  into  it  and 
out  again  at  the  lower  end  have  rinsed  out  the  salt 
and  left  it  sweet. 

Salt  lakes  almost  always  have  other  settlings  form- 
ing layers  at  the  bottom  besides  salt.  One  of  these  is 
plaster  of  Paris,  or  gypsum.  This  is  dissolved  in  the 
water  of  the  lake,  but  as  the  water  becomes  more  and 
more  salty  it  finally  settles;  then,  as  the  water  gets 
all  the  salt  in  it  that  it  can  dissolve,  salt  begins  to  set- 
tle above  the  gypsum,  and  we  generally  find  a  layer 
of  gypsum  and  then  one  of  salt,  and  dirt  washed  down 
by  the  summer  floods  over  them  both. 

Just  as  under  coal-beds  iron  is  found,  so  under  salt- 
beds  gypsum  is  found.  The  salt  accumulates  in  great 
masses  and  cakes.  Sometimes  it  is  lifted  by  fire  up 
into  mountains ;  and  at  the  lower  end  of  the  Dead  Sea 
there  are  great  masses  of  salt  reaching  several  miles  in 
length,  and  in  some  places  four  hundred  feet  in  height. 
The  rain-storms  have  worn  and  melted  it  till  it  stands 
in  buttresses  and  pillars.  At  the  foot  of  the  hills  these 
monuments  stand,  strewn  around  with  great  lumps  of 
pinkish  salt,  soft  and  slushy  in  winter,  but  sparkling 
with  brilliant  crystals  under  the  hot  summer's  sun. 


Salt.  183 

In  Louisiana,  among  the  low  prairies,  where  Evan- 
geline,  in  Longfellow's  beautiful  poem,  sought  her 
lover,  there  rise  five  humps  of  land  partly  surrounded 
by  water,  called  islands.  One  of  these  contains  one 
of  the  most  \vonderful  salt-mines  in  America.  During 
the  war  the  terrible  want  of  salt  made  the  owner  of 
this  island  dig  for  it.  After  digging  for  days,  some 
hard  substance  was  struck,  black  and  solid.  It  was 
at  first  thought  to  be  a  stump,  but  a  few  blows  of  the 
pick  and  out  flew  a  pure  white  piece  of  salt.  It  had 
been  covered  with  a  coat  of  black  asphalt.  It  is  not 
known  how  deep  this  salt-bed  is,  but  no  bottom  had 
been  touched  after  digging  through  sixty-five  feet  of 
pure  salt.  At  one  place  in  Europe  a  mine  has  been 
sunk  for  one  thousand  feet  and  no  bottom  found. 

Near  where  famous  old  Troy  stood  are  some  mar- 
vellous salt  springs.  The  place  is  a  valley  enclosed 
in  mountains,  colored  by  the  minerals  in  the  water — 
gorgeous  reds  and  blues  and  yelloAvs.  The  floor  of 
the  valley  is  a  variegated  crust,  through  which  jets  of 
hot,  intensely  salt  water  come  up.  In  one  place  from 
the  rocks  at  the  side  jets  of  boiling  water  spout  out 
like  fountains  at  play,  and  flow  away  as  a  rivulet  of 
salty,  steaming  water. 


CHAPTER  XVIII. 
THE  REIGN  OF  REPTILES. 

ONE  summer,  about  a  dozen  years  ago,  I  was  visit- 
ing Hartford,  Connecticut.  A  number  of  people  meet 
together  every  summer  in  some  part  of  the  United 
States,  to  discuss  questions  of  science.  After  the 
science  is  over  the  members  of  the  association  often 
go  upon  excursions. 

One  day  during  the  Hartford  meeting  the  geolo- 
gists and  others  paid  a  visit  to  a  very  wonderful  place 
on  the  Connecticut  Kiver,  near  Middletown,  called  the 
Portland  Quarries.  Quantities  of  brown  stone  for 
house  -  building  had  been  taken  out  and  shipped  to 
various  places.  This  quarrying  had  been  going  on 
for  about  one  hundred  years. 

In  one  place  a  broad,  uneven  floor  had  been  left  lit- 
tered over  with  slabs  of  stone  of  various  sizes.  On 
the  broken  bits  and  on  the  floor  were  great  numbers 
of  the  most  wonderful  footprints,  as  clear  and  distinct 
as  if  they  had  been  made  an  hour  before  in  wet  earth. 


The  Reign  of  Reptiles.  185 

Some  of  the  tracks  were  eight  or  ten  inches  in  length, 
others  were  not  more  than  four  or  five.  The  tracks 
looked  like  those  of  gigantic  birds,  and  were  called 
for  many  years  "the  bird -tracks  of  the  Connecticut 
Valley." 

The  sandstone  quarry  had  once  been  the  beach  of  a 
shallow  sea.  Over  the  sand  which  had  been  left  wet 
by  the  receding  water  myriads  of  strange  creatures 
roamed  in  search  of  food.  More  than  fifty  different 
kinds  of  creatures  have  left  a  record  of  their  presence 
on  this  shore,  and  there  were  probably  hundreds  upon 
hundreds  of  each  kind.  On  this  single  slab  of  stone, 
six  feet  by  eight,  and  dug  from  one  of  the  quarries  of 
the  valley,  are  the  tracks  of  six  different  creatures, 
inhabitants  of  that  ancient  world  (Fig.  67). 

Before  the  footprints  had  lost  their  distinctness,  the 
next  tide,  rising  and  sweeping  inland,  carried  a  new 
supply  of  sand  and  spread  it  over  the  beach,  covering 
the  footprints  and  making  a  fresh,  smooth  surface  for 
new  ones.  So  layer  after  layer  was  formed,  each  hold- 
ing the  record  left  of  their  presence  by  the  visitors  of 
the  day.  Slowly  the  whole  mass  hardened  into  stone, 
keeping  through  thousands  of  years  the  marks  im- 
pressed upon  it  when  it  was  yielding  sand. 


186 


The  Earth  in  Past  Ages. 


The  sandstone  readily  splits  between  any  two  lay- 
ers. When  an  upper  slab  is  turned  over,  the  same 
footprint  is  found  upon  it  as  was  upon  the  one  below 
it,  only  the  print  is  raised  instead  of  being  hollowed 


Fig.  67. — SLAB  OF  SANDSTONE,  WITH  TRACKS  OF  BIPEDS. 
Prom  Wiuchell's  "Sketches  of  Creation." 

out,  just  as  the  sealing-wax  on  a  letter  shows  the  same 
figure  raised  upon  it  which  was  hollowed  out  on  the 
seal  that  pressed  it. 

The  markings  so  long  considered  to  be  bird-tracks 


The  Reign  of  Reptiles.  187 

are  now  thought  to  have  been  made  by  a  strange 
winged  reptile  with  bird-like  claws,  whose  bones  have 
been  found  in  the  rocks  of  that  time.  It  is  not  so 
singular  as  it  may  seem  at  first  glance  that  such  doubt 
exists.  Eeptiles  and  birds  are  nearer  cousins  than  one 
would  be  apt  to  guess.  They  are  really  only  two 
branches  of  one  great  division  of  the  animal  world. 
Now,  it  is  true,  we  find  them  very  widely  separated, 
but  if  we  could  see  some  of  these  old-time  monsters  it 
would  puzzle  us  to  tell  whether  they  were  birds  or 
reptiles. 

These  tracks  in  the  sandstone  may  have  been  made 
by  a  reptile-like  bird,  but  more  probably  they  were 
those  of  a  bird-like  reptile. 

"When  a  reptile  is  spoken  of,  the  idea  it  suggests  is 
a  snake,  as  snakes  are  the  commonest  of  the  reptile 
class  in  our  time  and  our  country.  There  are,  how- 
ever, many  creatures  living  on  the  earth  now  which 
are  just  as  truly  reptiles  as  snakes  are ;  we  may  not 
see  many  of  these  creatures,  but  we  often  hear  or  read 
of  them — crocodiles,  and  their  American  cousins  alli- 
gators, turtles  or  tortoises,  and  lizards.  These  do  not 
form  a  very  important  class  in  the  animal  kingdom 
now,  but  there  was  a  time  in  the  world's  history  when 


188  The  Earth  in  Past  Ages. 

they  were  the  rulers  everywhere,  in  the  air  and  the 
sea  and  the  land.  There  were  probably  more  in  num- 
ber and  more  in  kind  than  the  world  has  seen  before 
and  since,  and  besides  this,  they  were  enormously 
larger,  more  powerful,  and  more  dangerous.  Many 
of  these  creatures  were  forty  feet  long,  and  some  were 
as  much  as  sixty  or  seventy  feet. 

The  reptiles  that  ruled  in  the  air  were  utterly  un- 
like anything  we  now  see.  Some  of  them  were  twen- 
ty feet  from  tip  to  tip  of  their  out-spread  wings.  One 
of  them,  you  see  (Fig.  69),  has  just  thrown  himself 
from  a  rock  in  pursuit  of  a  dragon-fly,  while  his  com- 
panion sits  perched  above  him  on  the  top  of  the  bank. 

Another  of  these  singular  creatures  may  be  seen  in 
Figure  70,  leaving  behind  it,  as  it  walks,  the  prints  of 
its  bird-like  claws  and  sharp  tail  and  queer  wings.  The 
wings,  you  see,  are  nothing  like  a  bird's  wings ;  they 
are  more  like  those  of  a  bat,  the  skin  being  stretched 
to  a  bone  of  the  fore-foot  from  the  side  of  the  body. 

Terrible  frog -like  animals  roamed  over  the  land, 
leaving  footprints  curiously  like  the  impression  from 
a  flat  human  hand  (Fig.  72). 

The  shores  of  the  ancient  seas  were  infested  with 
other  huge  beings  something  like  our  alligators.  In 


The  Reign  of  Reptiles. 


191 


Fig.  69. — THE  PTERODACTYL. 
From  Winchell's  "Sketches  of  Creation.' 


the  landscape  (Fig.  68)  one  of  these  may  be  seen,  in  the 
middle  of  the  picture,  crawling  up  on  a  rock,  while 
the  huge  frog-like  reptile  is  making  his  lumbering  way 
down  to  the  water,  where  he  spent  most  of  his  time. 


192  The  Earth  in  Past  Ages. 

It  was  the  ocean,  however,  in  which  most  of  the 
monsters  of  that  time  lived.  The  waters  of  its  seas 
were  lashed  into  fury  by  their  sports  and  spoutings 
and  battles  to  the  death.  Such  a  battle  is  shown  in 


Fig.  70. — RAMPHORHYNCUS — ONE-QUARTER  NATURAL  SIZK. 
From  Winchell's  "  Sketches  of  Creation." 

the  picture  (Fig.  71).  The  larger,  to  the  left,  must  have 
been  a  terror  to  the  watery  world  around  him.  Not 
content  with  devouring  all  the  fish  and  lizards  that 
came  in  his  way,  he  also  lived  upon  the  young  of  his 
own  kind,  as  the  bones  found  in  the  stomach  of  a  skel- 
eton show. 


The  Reign  of  Reptiles. 


195 


The  huge  sea-lizard  to  the  right  in  the  same  picture 
was  a  much  less  dangerous  creature.  At  this  time 
there  existed  creatures  more  nearly  approaching  ser- 
pents ;  these  have  sometimes  reached  a  length  of  eighty 
feet.  It  is  possible  that  some  of 
his  cousins  still  exist  in  the  ocean, 
and  that  they  occasionally  show 
themselves.  There  have  been  a 
great  many  stories  of  sea-serpents 
seen  by  many  people  and  at  va- 
rious times.  Most  of  these  are 
undoubtedly  sailors'  yarns,  and 
deserve  no  attention ;  but  leaving 
these  out  of  the  question,  there 
still  remain  some  that  we  cannot 
refuse  to  credit — one  of  these,  for 
instance,  where  five  hundred  people  saw  the  creature 
again  and  again,  and  near  enough  to  distinguish  its 
eyes;  and  some  of  these  witnesses  Avere  men  whose 
evidence  would  have  been  taken  in  any  court  of  jus- 
tice in  the  land.  Not  very  long  ago  a  strange  car- 
cass was  caught  in  the  anchor  of  a  sailing-vessel  and 
beached  on  the  Florida  coast.  A  storm  washed  it 
away  before  such  drawings  and  measurements  could 


Fig.  72. — TRACKS  OF  LABY- 

RINTHODON. 

From  Lyell's  "Elements  of 
Geology." 


196  The  Earth  in  Past  Ages. 

be  made  as  would  have  settled  the  question  as  to 
what  it  was.  Now  that  people  are  seriously  begin- 
ning to  listen  to  stories  of  the  sea-serpent,  we  may 
hope  that  some  day  one  will  be  captured,  and  then 
all  doubts  as  to  its  existence  and  what  manner  of  rep- 
tile it  really  is  will  be  finally  set  at  rest. 

During  the  age  of  reptiles  many  new  shells  and 
stone-lilies,  etc.,  first  appeared  in  the  waters;  but  they 
were  not  sufficiently  unlike  those  that  had  already 
come  and  those  that,  folio  wed  after  to  require  descrip- 
tion here. 

The  character  of  the  forests,  too,  was  changing  all 
the  while  from  what  it  had  been  in  the  coal-making 
period.  The  great  club  mosses  with  their  carven  stems, 
and  the  huge,  feathery-leaved  reeds,  were  passing  away. 
The  ferns  still  grew  in  great  profusion ;  both  the  low 
and  creeping  kinds  and  the  tree-ferns  filled  the  woods, 
but  other  trees  and  plants,  like  our  evergreens  and 
palms,  took  the  place  of  vanishing  kinds.  These,  too, 
made  coal-beds,  though  not  such  vast  ones  as  were 
stored  away  during  the  reign  of  plants. 

It  must  be  understood  that  the  whole  world,  Europe 
and  America  and  Australia,  had  each  its  history,  when 
the  reign  of  water  and  fire  and  ice,  of  plants  and  ani- 


The  Reign  of  Reptiles.  197 

mals,  followed  each  other  very  much  in  the  same  way, 
but  not  at  the  same  time.  Europe  is  an  older  country 
than  America,  and  America  is  older  than  Australia,  in 
other  things  besides  those  about  which  our  written 
histories  tell  us.  The  animals  and  plants  of  America 
when  it  was  first  discovered  were  like  those  of  Europe 
in  a  time  much  earlier.  Australia  had  animals  and 
plants  that  corresponded  with  an  age  still  earlier  than 
those  of  America.  Some  of  the  curious  birds  and  ani- 
mals of  Australia  help  us  to  understand  the  meaning 
of  the  singular  skeletons  dug  out  of  the  rocks  in  Eu- 
ropean countries. 

In  the  history  of  each  country,  after  man  came 
upon  the  earth,  we  see  something  like  this.  When 
Eome  was  in  its  later  days,  England  was  full  of  bar- 
barians ;  and  England  was  an  old  country,  in  her  turn, 
when  America  was  still  barbarous.  Just  as  man's 
work  in  the  world  —  his  diggings  and  minings  and 
quarryings — changes  the  order  of  nature  in  the  layers 
of  the  earth,  so  his  moving  in  and  taking  possession 
of  the  new  countries  changes  the  order  of  things  there 
too,  and  interferes  with  the  regular  succession  of  creat- 
ures which  would  have  followed,  one  kind  succeeding 
another  till  all  was  complete, 


CHAPTER  XIX. 

THE  BOTTOM  OF  THE  SEA. 

ABOUT  three-quarters  of  our  world  is  under  water. 
This  we  all  know  very  well,  if  we  have  not  grown  so 
old  or  so  wise  as  to  have  forgotten  our  geography. 
We  are  apt  to  think  of  this  vast  expanse  of  ocean  as 
having  very  few  inhabitants ;  in  fact,  as  being  a  sort 
of  watery  great  desert,  with  fish  passing  through  it, 
something  as  the  caravans  pass  over  Sahara.  It  is 
chiefly  important  to  us  as  the  path-way  over  which 
steamships  and  sailing-vessels  go,  carrying  passengers 
and  exchanging  the  products  of  one  country  for  those 
of  others. 

But  the  ocean  is  even  more  than  the  land  teeming 
with  life.  Not  only  are  its  waters  full  of  darting  fish, 
but  there  is  a  silent  life  filling  the  sea-bottom,  and  do- 
ing more  towards  building  it  up  than  all  the  larger 
creatures  above.  And  so  it  was  in  the  past  ages,  only 
more  truly  so.  Large  as  the  ocean  is  now,  it  was  far 


The  Bottom  of  the  Sea.  199 

larger  then.  The  Atlantic  waves  as  they  swept  west- 
ward did  not  break  upon  the  coast  of  the  British  Isl- 
ands, for  England,  Ireland,  and  Scotland  were  deep 
down  under  water.  The  inhabitants  of  the  British 
Isles  in  that  day  Avere  principally  little  shell-fish,  so 
tiny  that  you  could  not  have  seen  what  they  were 
with  your  unaided  eye.  As  each  generation  of  these 
little  creatures  died,  these  shells,  some  of  glass  and 
.others  of  a  limy  or  chalky  substance,  beautifully 
formed  and  delicately  carved,  dropped  to  the  bottom, 
and  so  built  up  the  earth.  There  was  nobody  around 
then  with  his  magnifying-glass  to  look  at  the  curious 
earth  as  it  was  forming,  but  it  has  been  saved  for  us 
in  one  of  the  great  layers  of  earth  called  "  the  chalk." 
Much  of  England  was  built  up  in  this  way  by  the 
dropping  of  myriads  of  shells  when  the  little  life  that 
had  animated  it  went  out.  At  the  end  of  the  English 
chalk  period  Great  Britain  and  more  besides  were 
lifted  bodily  above  the  waters,  and  then  the  waves 
went  to  work  to  carve  England,  with  all  her  bays  and 
inlets,  out  of  the  great  stretch  of  uplifted  land.  The 
Strait  of  Dover  was  cut  through,  leaving  the  edges 
of  the  chalk  layer  standing  up,  white  and  tall,  facing 
the  water. 


200 


The  Earth  in  Past  Ages. 


Fig.  73. — CHALK  CLIFFS  OF  DOVER. 

These  chalk  cliffs  gave  the  poetical  name  of  Albion, 
or  the  white,  to  England ;  and  these  were  the  shores 
to  which  the  men  of  Tyre  and  Sidon  came  in  their 
ships  to  gather  the  tin  found  in  the  southern  counties 


The  Bottom  of  the  Sea. 


201 


of  England,  and  carry  it 
away  to  their  own  land, 
long  before  our  Lord  was 
born  in  Bethlehem. 

Though  England  was  no 
longer  receiving  new  lay- 
ers of  shells,  the  same 
thing  went  on  and  is  go- 
ing on  to-day  in  por- 
tions Of  the  Atlantic  Fig.  74.— ENGLISH  CHALK. 

Ocean.       The   difference     • 

between  the  chalk  formed  so  many  millions  of  years 
ago  and  that  forming  now  you  can  see  by  looking  at 

Figure  74,  from  the  Eng- 
lish chalk-beds,  and  then 
comparing  it  Avith  Figure 
75,  from  the  bottom  of 
the  Atlantic  to-day. 

Yery  little  was  known 
of  the  great  oceans  before 
the  days  of  Columbus  and 
the  other  voyagers  of  his 
time.  All  the  sailing  done 
Fig.  75.— ATLANTIC  DREDGING.  before  that  was  in  inland 


202  The  Earth  in  Past  Ages. 

seas  like  the  Mediterranean,  or  along  the  shores.  And 
people  imagined  that  down  in  the  depths  the  cold  and 
darkness  and  tremendous  weight  of  the  water  would 
prevent  anything  from  living  there.  A  few  examina- 
tions were  made,  it  is  true,  in  a  part  of  the  Mediter- 
ranean near  Greece,  and  no  life  being  found  there, 
that  settled  the  question  for  a  while. 

But  just  thirty  years  ago  men  of  science  found  oc- 
casion to  change  their  minds  upon  this  point.  A  tel- 
egraphic cable  which  had  been  lying  in  deep  water 
(the  exact  depth  was  known)  was  broken.  In  order 
to  mend  it  the  cable  had  to  be  drawn  up  out  of  the 
water.  When  this  was  done,  thousands  of  tiny  living 
creatures  were  found  on  the  wire.  Not  loose,  as 
though  they  had  been  caught  on  the  cable  as  it  was 
dragged  up  through  the  waters,  but  closely  cemented 
to  it,  showing  that  they  had  lived  where  the  wire  was 
lying  in  the  depths  of  the  sea. 

As  soon  as  the  fact  was  known  that  there  was  life 
in  the  sea-depths  a  great  interest  was  aroused.  Ships 
were  fitted  up  with  all  sorts  of  dredges  and  scoops  and 
nets  to  catch  the  delicate  creatures  living  down  deep 
in  the  water,  and  to  bring  up  the  soil  from  the  bottom 
so  gently  that  its  inhabitants  would  not  be  killed. 


The  Bottom  of  the  Sea.  203 

Day  by  day  the  formation  of  chalk,  as  it  is  going  on 
now  at  the  sea-bottom,  was  watched  and  recorded. 

Nowhere  else  do  we  find  a  link  that  binds  our 
world  of  to-day  so  closely  with  the  far  distant  past 
as  just  here.  The  higher  the  form  of  life,  the  more 
easily  does  it  change  and  develop.  We  find  in  the 
mud  from  the  Atlantic  bottom  living  creatures  whose 
shells  are  very  much  the  same  as  those  which  millions 
of  years  ago  built  up  the  English  chalk.  These  are 
almost  unchanged,  while  above  them  all  the  wonder- 
ful panorama  of  life  has  passed  unnoticed.  The  strange 
fish  and  monstrous  reptiles  and  curious  reptilian  birds 
have  all  passed  and  vanished  utterly  from  the  earth, 
the  water  and  the  air  knowing  them  no  more. 

The  reason  of  this  is  clear.  All  life  depends  much 
on  its  surroundings :  if  they  remain  the  same,  the 
forms  of  life  usually  do  not  change  much.  On  land 
and  on  the  surface  of  the  water  the  surroundings  con- 
stantly vary.  Heat  and  cold,  moisture  and  drought 
and  plant  life,  have  changed,  and  the  animal  life  has 
changed  with  them,  but  in  the  depths  of  the  sea  there 
has  been  only  one  marked  change — the  waters  have 
been  slowly  cooling  off,  and  so  the  changes  have  been 
slight  and  gradual.  Everything  else  remaining  the 


204: 


The  Earth  in  Past  Ages. 


same,  we  ought  not  to  expect,  and  we  do  not  find, 
any  violent  change  in  the  forms  of  deep-sea  life.  The 
geologic  period  of  the  Atlantic  depths  is  therefore  not 
far  from  that  of  the  British  Isles  some  millions  of 
years  ago. 

It  perhaps  seems  like  going  backward  instead  of 
forward  when  we  take  up  the  study  of  these  tiny, 
simple  forms  of  life,  after  the  mighty  reptiles  that 
have  ruled  with  a  rod  of  iron  the 
world  of  waters.  But  we  are  go- 
ing upward  through  the  layers  of 
rock,  and  after  the  coal-fields  and 
the  rocks  that  contain  the  foot- 
prints and  bones  of  the  reptiles, 
come  these  beds  made  of  tiny 
glass  and  chalky  shells.  The  rea- 

gon      f  thj     •     th   t  t  tractg      f 

land  sank  under  the  sea,  and  over 
it  settled  myriads  of  the  chalk  shells,  forming  a  thick 
layer.  These  little  creatures  had  been  living  from  the 
earliest  ages.  Indeed,  the  Eozoon — the  dawn-animal — 
the  earliest  form  we  know — was  cousin  to  these  sea- 
shells,  which  you  may  see  in  the  illustration  called 
English  Chalk. 


Fig.  76. — ECHINUS  (Fossil 
Sea-urchin). 

From  Lyell's  "Elements  of 
Geology." 


The  Bottom  of  the  Sea. 


205 


Though  these  tiny  shell- 
fish made  so  much  of  the 
land  at  that  time  as  to  give 
a  name  to  the  period,  the 
chalk,  there  were  existing  at 
the  same  time  a  great  many 
other  forms  of  life.  Sea- 
urchins  abounded  (Fig.  76),  F's'  «-COR^  «  C«^K- 

,     ,.„.  ,        ,         a,  Natural  size;   6,  Part  of  the  same 

and  corals  (Fig.  77),  and  oth-  magnified. 

er    Shell -fish    (Fig.  78),    also     From  Lyell's"  Elements  of  Geology." 

other    foims, 

called  glass  sponges,  living  with  shell-fish 

as  they  do  now. 

In  the  depths  of  the  Philippine  seas, 
nearly  three-quarters  of  a  mile  straight 
down,  live  the  most  beautiful  of  the  glass 
sponges  nowadays.     They  are  almost  the 
most  beautiful  of  all 
nature's  works — long 
curved    cornucopias 
made    of    the    finest 
spun  glass  woven  into 
TURRILITE.  SCAPHITE.  a  square-meshed  lace. 

From  Lyell's  "Elements  of  Geology."  ArOUnd   the   hom    run 


Fig.  78. 


206 


The  Earth  in  Past  Ages. 


short  frills  of  delicate  lace,  while  the  small  end  of  the 
horn  is  enclosed  in  a  tuft  of  the  silvery  hair.  This 
beautiful  thing  is  second -cousin  to  our  common 
drudge  of  a  sponge,  and  nearer  still  to  the  glass 
sponges  among  the  chalk  (Fig.  79).  Whenever  you 
are  in  a  museum,  ask  to  see  the  Ye- 
nus's  Flower-pot,  for  that  is  the  name 
of  this  particular  kind  of  a  glass 
sponge. 

While  the  earth  was  being  slowly 
built  up  by  these  beautiful  beings  un- 
der the  sea,  you  may  be  sure  the  land 
was  not  empty.  Enormous  lizard-like 
creatures  wandered  over  the  shores 
or  slipped  heavily  into  the  water. 
Great  flying  lizards  beat  the  air  as 
they  rushed  downward  from  some 
high  tree  or  lofty  rock.  There  were 
fifty  different  kinds  of  immense 
snake -like  creatures,  some  of  them 
eighty  feet  long.  The  reign  of  reptiles  was  drawing 
to  a  close,  but  it  was  not  over.  There  are  on  the 
earth  now  only  six  large  kinds  of  reptiles,  and  these 
not  over  twenty-five  feet  in  length. 


Fig.  79. — SPONGE  OP 
CHALK. 

Prom  Lyell's  "  Elements 
of  Geology." 


The  Bottom  of  the  Sea.  207 

There  were  still  very  few  beings  above  the  reptile 
class,  but  the  highest  forms  were  beginning  to  be  shad- 
owed forth  by  a  class,  the  lowest  of  the  quadrupeds, 
to  which  the  kangaroo  and  opossum  of  our  time  be- 
long. These  creatures  have  a  pouch  in  which  the  un- 
formed young  are  kept  till  they  are  fully  developed. 

The  climate  must  have  been  warm  all  over  the 
earth.  The  plants  and  animals  that  existed  in  all 
parts  of  the  world  in  those  days  live  only  in  the  hot- 
test countries  now.  The  forests  through  which  the 
reptile  monsters  roamed  were  made  up  of  tree-ferns 
and  palms,  in  the  island  of  Spitzbergen,  where  there 
is  now  perpetual  ice  and  snow. 

At  the  end  of  this  period  a  great  change  took  place 
in  the  New  World.  North  and  South  America  had 
been  up  to  this  time  two  islands,  widely  separated. 
By  an  uplifting  of  the  western  part  of  the  two  islands 
the  land  that  connected  them  under  the  sea  was  raised 
above  water,  and  the  continent  of  America  was  born 
out  of  the  sea.  This  was  the  age  of  continent  and 
mountain  making.  A  map  of  America  before  this 
upheaval,  and  one  afterwards,  do  not  look  as  though 
they  were  made  to  represent  the  same  world,  they 
are  so  very  different. 


CHAPTER   XX. 
BIRDS  OF  THE  PAST. 

ONE  period  in  the  building  up  of  the  earth  we  have 
called  the  Reign  of  the  Fishes,  for  two  reasons :  first, 
because  the  greatest  and  most  terrible  of  living  creat- 
ures were  of  the  fish  tribe  ;  second,  because  the  fish 
were  at  that  time  the  highest  kind  of  animal  living. 
Another  and  a  later  period  was  for  the  same  reason 
called  the  Reign  of  Reptiles.  Other  and  lower  creat- 
ures lived  in  great  multitudes,  but  the  reptiles  were 
the  mightiest. 

Birds  lived  in  geologic  times,  too,  quite  as  wonderful 
and  monstrous  as  either  fish  or  reptile,  but  there  was 
no  one  time  that  could  be  correctly  called  the  age  of 
birds.  lThey  never  had  a  distinct  reign  of  their  own. 

This  seems  a  little  strange,  for  there  is  no  class  of 
living  creatures  that  seems  so  entirely  distinct  and 
separate  from  the  rest  of  the  animal  world  as  birds. 
They  have  so  many  peculiarities  all  to  themselves ; 


Birds  of  the  Past.  200 

their  horny  bills  and  feathers  and  wings,  their  power 
of  flight  and  of  song,  seem  to  set  them  apart  from 
other  living  beings.  And  so  we  might  very  naturally 
expect  to  find  in  the  past  a  reign  of  birds. 

You  remember  that  the  arrangement  that  was  given 
to  the  different  kinds  of  living  creatures  by  natural- 
ists, beginning  at  the  simplest  kind  of  life  and  going 
gradually  up,  was  found,  when  geology  began  to  be 
studied,  to  correspond  very  nearly  with  the  order  of 
animal  life  found  in  the  rocks,  beginning  at  the  lowest ; 
that  is,  men  studying  the  works  of  God,  and  arranging 
them  in  classes,  followed  almost  the  same  order  that 
God  had  followed  in  creating  them. 

But  there  was  one  point  where  the  order  of  science 
was  found  to  be  different  from  the  order  of  nature. 
Men  put  birds  next  after  reptiles,  while  in  the  rocks 
they  were  found  to  be  side  by  side.  This  looks  as  if 
there  must  be  a  mistake  somewhere.  But  there  is  no 
mistake ;  in  this  seeming  difference  is  hidden  a  won- 
derful natural  truth.  Birds,  as  we  know  them  now, 
seem  quite  as  far  removed  from  reptiles  as  they  are 
from  fish  or  from  quadrupeds ;  but  this  is  only  seem- 
ing. Birds  are,  as  a  matter  of  fact,  only  one  great 
branch  of  the  reptile  family ;  but  they  have  been  sep- 


210  The  Earth  in  Past  Ages. 

arated  so  many  millions  of  years  that  the  family  like- 
ness is  not  very  strong.     That  they  once  belonged  to 
the   same  family,  geology,  more  than 
anything  else,  tells  us. 

Don't  you  remember,  in  Chapter 
XVIL,  the  Eeign  of  Eeptiles,  the  cu- 
rious footprints  that  were  sometimes 
taken  for  bird -tracks  and  sometimes 
for  the  tracks  of 
reptiles?  Well, they 
were  made  by  creat- 
ures that  had  a  good 
deal  of  both  bird 
and  reptile  in  them. 
Their  footprints  told 
the  tale.  In  Figure 
80  you  see  the  out- 
line of  one  of  these 
queer  bird-like  rep- 
tiles, and  there  were  many  others,  as  well  as  reptile- 
like  birds. 

The  manner  in  which  such  tracks  were  preserved  in 
the  sand,  and  retained  when  it  was  baked  and  pressed 
into  stone,  is  very  easy  to  understand.  Where  the 


Fig.  80. — BIRD  LIKE  REPTILE. 


Birds  of  the  Past.  211 

tracks  are  found  was  a  shallow  inland  sea,  connected 
with  the  ocean  by  a  narrow  strip  of  water.  The  tides 
flowed  in,  deposited  the  sand  that  they  had  swept  up 
with  them,  and  then  flowed  out,  leaving  a  coating  of 
wet,  smooth  sand  behind.  This  is  shown  in  several 
ways.  Slabs  of  sandstone  are  often  found,  as  we  have 
seen,  with  ripple  marks  as  perfectly  distinct  as  if  it 
were  moist  sand  that  the  water  had  washed  an  hour 
before. 

On  the  wet  sand  of  the  shore  many  strange  creat- 
ures, reptiles  and  birds  especially,  came  in  search  of 
food  cast  up  by  the  tide.  They  left  distinct  tracks  in 
the  sand,  which  caked  in  drying.  The  next  tide  would 
bring  in  more  sand  and  spread  it  over  these  tracks, 
and  this  would  happen  again  and  again.  When  it  all 
hardened  and  became  stone,  the  footprints  and  ripples 
and  rain-drops  would  remain  unchanged ;  and  when 
the  sandstone  was,  ages  and  ages  afterwards,  broken 
with  the  pick,  it  would  naturally  split  between  the 
layers,  and  show  the  marks. 

The  first  bird  found  in  the  rocks  is  a  most  wonderful 
creature.  Near  Munich,  in  Bavaria,  there  is  a  quarry 
of  stone  which  is  quite  celebrated  because  the  chalky 
slate  taken  out  of  it  is  used  for  lithographic  engrav- 


212 


The  Earth  in  Past  Ages. 


ings  and  chromos,  and  is  perhaps  the  best  in  the  world 
for  that  purpose.  Slate,  you  know,  splits  in  thin  lay- 
ers; this  is  partly  because  it  was  laid  down  by  the 


Fig.  81. — TAIL  AND  FEATHER  OP  REPTILE-LIKE  BIRD,  WITH  TAIL  OP  MOD- 
ERN BIRD  FOR  COMPARISON. 

Prom  Lyell's  "Elements  of  Geology." 

water,  layer  on  layer,  and  partly  also  because  it  has 
been  subjected  to  enormous  pressure,  and  it  splits  in 
one  direction,  just  as  pie-crust  does  from  the  pressure 
of  the  rolling-pin. 


Birds  of  the  Past. 


213 


In  between  two  layers  of  this  slate,  about  thirty 
years  ago,  a  single  but  perfect  feather  was  found  (Fig. 
81,  A) ;  this  is  the  first  trace  of  the  earliest  bird  known. 
Soon  another  specimen  was  found ;  this  was  the  hinder 
parts  of  a  very  strange  creature,  with  tail  feathers 
growing  out  of  each  side  of  a  reptile-like  tail.  Figure 


Fig.  82.— SKELETON  IN  STONE  OF  REPTILE-LIKE  BIRD. 


214  The  Earth  in  Past  Ages. 

81,  B,  is  the  tail  of  the  bird  of  the  slate ;  C  shows  the 
tail  of  the  birds  we  have  now.  You  see  how  differ- 
ently the  feathers  are  attached.  Some  years  later  a 
slab  of  this  same  stone  was  found.  A  blow  of  the 
hammer  and  it  fell  open,  showing,  after  careful  work- 
ing, bones,  wings,  tail,  and  head,  which  you  see  in  Fig- 
ure 82  just  in  the  position  in  which  they  lay. 

Several  attempts  have  been  made  to  draw  the  ani- 
mal or  bird  to  which  this  skeleton  belonged.  Figure 
83  is  one  of  these,  and  if  you  compare  part  by  part 
you  will  see  how  closely  the  skeleton  is  followed. 
There  is  nothing  to  indicate  that  this  curious  creature 
had  any  feathers  on  its  body.  This  is  about  as  far 
from  our  idea  of  a  bird  as  anything  could  well  be, 
apart  from  its  feathers  and  its  legs.  Notice  the  claws 
on  the  ends  of  the  wings,  its  lizard-like  head,  arms, 
and  teeth. 

America  has  added  of  late  years  a  large  number  of 
reptile-like  birds.  They  come  mainly  from  New  Jer- 
sey and  Kansas.  Among  them  are  waders,  swimmers, 
and  divers.  Some  of  them  were  evidently  flying  birds, 
for  they  have  the  keel  down  the  breastbone,  which 
sustains  the  muscles  of  the  wings.  This  keel  you  have 
often  seen  when  the  white  meat  is  cut  from  a  chicken 


Fig.  83.— THE  EARLIEST  BIRD  (Archceopteryx). 
Restored  by  R.  W.  Shufeldt. 


Birds  of  the  Past.  217 

or  turkey.  Others,  like  the  ostrich,  which  do  not  fly, 
but  assist  themselves  with  their  small  wings  in  run- 
ning, have  no  keel.  Six  kinds  of  the  American  rep- 
tile-birds have  teeth,  a  thing  no  living  bird  has  nowa- 
days. The  two  great  branches  of  the  reptile  family 
were  not  then  disentangled  and  separated  from  each 
other ;  so  that  the  birds  still  had  some  things  left  from 
their  reptile  forefathers,  and  the  reptiles  had  not  lost 
certain  other  things  which  afterwards  disappeared  in 
their  branch,  but  were  kept  and  developed  by  the  birds. 
There  are  very  few  bird  skeletons  in  the  rocks — 
few  even  when  compared  with  the  bones  of  fish  and 
reptiles.  The  reason  of  this  is  not  far  to  seek.  In  our 
own  times,  when  the  woods  are  full  of  birds,  many 
thousands  must  of  course  die  every  year,  and  yet  who 
ever  sees  a  bird  skeleton  after  the  feathers  and  flesh 
are  gone?  A  large  part  of  the  bones  of  animals  are 
gnaAved  by  other  creatures,  broken  up,  or  decayed, 
and  so  blow  away  and  are  lost.  What  is  true  of  all 
wild  creatures  is  especially  true  of  birds.  If  they  fall 
on  land,  they  fare  like  everything  else ;  but  if  they  fall 
in  the  water,  instead  of  sinking  and  being  covered  over, 
their  feathers  buoy  them  up,  and  keep  them  afloat  till 
they  are  beaten  about  and  destroyed.  It  was  only 


218 


The  Earth  in  Past  Ages. 


one  bird,  probably,  in  many  hundreds  of  thousands 
that  fell  in  the  right  place  on  the  sand  or  mud  at  the 
water's  edge,  near  enough  to  be  covered  by  the  next 
tide,  but  not  near  enough  to  be  washed  away ;  so  we 


are  rather  fortunate 
in  finding  traces  of 
so  many  of  these  del- 
icate creatures  in  the 
rocks.  As  time  went 
on,  the  birds  lost 
more  and  more  of 
their  reptile  features, 
and  became  gradual- 
ly like  the  birds  we  Fig.  84.— NEW  ZEALAND  BIRD,  LATELY  EXTINCT. 

now  know,  while  the 

reptiles  lost  their  bird-like  qualities — all  but  the  lay- 
ing of  eggs,  which  both  do  now. 

Although  there  is  no  time  that  could  properly  be 
called  the  reign  of  birds,  there  is  one  place  that,  when 
it  was  discovered  by  Europeans,  might  have  received 


Birds  of  the  Past.  219 

justly  the  title  of  the  Bird  Kingdom :  this  is  the  island 
of  New  Zealand,  near  Australia.  When  it  was  first 
visited  by  white  men  not  a  single  four-footed  beast 
was  found  upon  it,  large  or  small.  The  highest  form 
of  life  was  the  bird;  and  there  were  multitudes  of 
these,  closely  allied  to  the  birds  of  geology,  with  nei- 
ther wings  nor  tails  (Fig.  84) ;  and  great  quantities  of 
bird  skeletons  of  gigantic  size,  some  of  them  twelve  or 
fourteen  feet  high.  There  are  numbers  of  these  skel- 
etons at  the  Museum  of  Natural  History,  Eighty-sec- 
ond Street  and  Ninth  Avenue,  New  York ;  also  an  egg 
which  would  contain  as  much  as  one  hundred  and  fifty 
hen's  eggs. 


CHAPTER  XXI. 

THE  REIGN  OF  LAND  MONSTERS. 

You  remember,  I  hope,  that  the  four-footed  creat- 
ures had  begun  to  come  some  time  ago,  when  the 
chalk  and  limestone  were  forming  at  the  bottom  of 
the  sea ;  but  they  were  of  a  peculiar  kind,  like  the 
kangaroo  and  opossum.  These  creatures  are  called 
marsupials,  from  a  Latin  word  meaning  bag  or  pouch, 
because  the  mother  has  on  her  body  a  sort  of  pocket 
or  pouch,  in  which  her  tiny  babies  are  put,  and  there 
they  live  till  they  open  their  eyes,  and  are  strong 
enough  to  walk  about  alone. 

One  of  the  very  largest  land  animals  the  world  has 
ever  known,  it  is  believed  from  a  bone  lately  found, 
belonged  to  the  pouched  animals.  It  was  much  larger 
than  any  living  elephant,  though  looking  like  one, 
with  great  trunk  and  tusks  (Fig.  85).  It  was  related 
to  other  creatures  that  you  have  probably  seen  in  a 
menagerie,  the  rhinoceros  and  tapir  as  well  as  the  ele- 


The  Reign  of  Land  Monsters. 


221 


pliant.  One  curious  thing  about  the  animals  of  these 
long-past  days  is  that  they  are  not  like  any  of  the  liv- 
ing forms,  but  are  connecting  links  between  different 
kinds. 


Fig.  85. — DINOTHERIUM. 

The  great  four-footed  beasts  and  the  small  ones  are 
called  mammals,  because  their  young  live  upon  moth- 
er's milk.  Besides  the  land  animals  there  are  other 
mammals — whales  and  dolphins,  seals  and  bats.  The 
lowest  order  of  the  mammals  are  the  marsupials,  so 
they  naturally  were  the  first  in  the  order  of  creation. 

About  a  century  ago  Australia  was  scarcely  known. 


222  The  Earth  in  Past  Ages. 

When  it  began  to  be  settled  by  white  men  they  found 
living  in  it  very  singular  plants  and  animals,  unlike 
those  known  in  Europe.  Yery  nearly  at  the  same 
time  that  travellers  were  describing  the  curious  life  in 
Australia,  geologists  were  studying  the  bones  of  very 
queer  animals  which  had  been  dug  up  out  of  the 
earth ;  and  it  was  discovered  that  Australian  life  was 
very  much  more  like  that  which  had  been  in  Europe, 
thousands  upon  thousands  of  years  before  man  came 
upon  earth,  than  it  was  like  anything  then  existing  in 
the  known  world.  In  Australia  there  was  not  a  sin- 
gle mammal  higher  than  a  marsupial,  not  a  rat,  nor  a 
mouse,  nor  a  rabbit ;  nothing  but  kangaroos  and  opos- 
sums and  such  creatures.  It  was,  in  fact,  a  young 
earth,  not  yet  grown  up ;  it  had  only  reached  the 
marsupial  stage.  America  is  young  in  the  same  sense, 
but  not  so  young  as  Australia,  while  New  Zealand  is 
the  youngest  of  the  three.  It  has  only  grown  up  to 
the  bird  age.  Of  course,  when  these  countries  came 
to  be  settled  by  white  people,  plants  and  animals  from 
Europe  were  introduced,  and  the  changes  which  would 
have  taken  perhaps  millions  of  years  if  left  to  natural 
causes  were  in  this  way  greatly  hurried. 

The  knowledge  which  went  deeper  into  the  earth, 


The  Reign  of  Land  Monsters.  223 

geology,  and  the  knowledge  which  spread  wider  over 
its  surface,  natural  history,  thus  were  found  to  confirm 
and  explain  each  other. 

I  remember  reading  a  long  time  ago,  but  I  have 
never  been  able  to  find  it  since,  that  a  singular  bone 
found  in  the  earth  was  taken  to  Richard  Owen,  the 
man  who  perhaps  knew  more  about  bones  than  anj> 
man  of  his  day.  After  studying  it  carefully  he  said 
it  belonged  to  a  bird  without  wings  or  tail.  In  spite 
of  his  friends'  advice  to  keep  this  quiet,  as  being  prob- 
ably incorrect,  he  published  his  views.  These  were 
soon  after  confirmed  by  the  finding  of  a  wingless,  tail- 
less bird  in  New  Zealand.  This  is  a  good  example  of 
scientific  guessing. 

As  we  approach  the  coming  of  man  upon  the  earth, 
we  find  all  nature  beginning  to  put  on  the  look  so  fa- 
miliar to  us.  The  forests  were  made  up  of  trees  very 
like  those  we  now  know — oaks  and  elms,  walnuts  and 
birches,  interspersed  with  pines  and  firs,  yews  and 
cypresses.  The  fields  were  covered  with  grass  and 
flowers.  On  the  surfaces  of  quiet  ponds  the  water- 
lilies  spread  their  broad  leaves  and  opened  their  fra- 
grant flower-cups,  while  underneath  could  be  seen  the 
delicate  fronds  and  thread-like  leaves  of  water-plants, 


224 


The  Earth  in  Past  Ages. 


swaying  back  and  forth  with  every  gentle  movement 
of  the  water.  Mosses  and  liverworts  clothed  the  damp 
rocks  with  a  garment  of  living  green.  The  trees  and 

flowers  of  that  day  did 
not,  in  many  cases,  dif- 
fer from  ours ;  more 
than  one  kind  of  ma- 
ple, for  instance,  differs 
from  another  (Fig.  86). 
The  most  interesting 
thing  in  the  plant  life 
of  that  day  is  the  proof 
it  gives  of  difference  of 
climate  from  that  which 

exists  in  the  same  parts  of  the  world  now.  Mingled 
with  the  oaks  and  birches  of  our  zone  are  great 
palms  and  tree-ferns,  which  now  grow  only  in  very 
hot  countries.  The  cypresses  and  magnolias  that  to- 
day grow  in  the  swamps,  of  Carolina  and  Louisiana 
then  grew  in  Greenland.  There  is  strong  reason  to 
believe  that  America  was  joined  with  Europe  on  the 
east  by  way  of  Greenland,  Iceland,  and  Norway,  and 
that  at  the  same  time  it  was  joined  with  Asia  on  the 
west  across  Behring  Strait. 


Fig.  86.— MAPLE  LEAP. 
Prom  LyelPs  "Elements  of  Geology.1 


The  Reign  of  Land  Monsters.  225 

Among  the  shell-fish,  oysters  grew  in  great  abun- 
dance and  to  great  size,  and  the  rivers  were  filled  with 
eatable  fish,  shad  and  perch. 

One  very  wonderful  thing  in  that  time  was  the 
myriads  of  insects  that  filled  the  earth  and  air.  It 
would  seem  impossible  that  so  delicate  a  thing  as  an 
insect  could  be  kept  in  the 
rocks  all  these  thousands  of 
years  in  such  a  state  that  it 
could  be  recognized  (Figs.  87 
and  88),  and  yet  this  is  true, 
not  of  one,  but  of  hundreds 
of  varieties.  Uncounted  mill- 
ions of  insects  of  various  kinds 
perished,  and  are  found  packed 
in  solid  layers  in  the  rocks. 
How  this  happened  we  may 
guess  from  something  that 
Professor  Le  Conte  tells  us. 
He  says  that  he  has  seen,  af- 
ter a  storm,  on  the  sands  that 
border  Lake  Superior,  millions  of  insects  that  had 
been  drowned  and  washed  ashore,  till  the  banks  were 
black  with  them.  A  layer  of  sand,  washed  up  by 
15 


Fig.   87.  —  INSECT    FOUND    IN 
KOCK. 

From  Lyell's  "  Elements  of  Geol- 
ogy." 


226 


The  Earth  in  Past  Ages. 


the  beating  waves,  and  deposited  on  top  of  these, 
would  preserve  them,  as  the  insects  of  old  were  pre- 
served. 


Fig.  88. — BUTTERFLY  FOUND  IN  ROCK. 
From  Lyell's  "Elements  of  Geology." 

In  the  whole  of  Europe  there  are  now  only  fifty 
species  of  ants  known,  but  in  a  layer  of  rock  in  Switz- 
erland one  hundred  species  have  been  found,  and  these 
were  all  winged  ants.  In  a  colony  of  ants  of  our  day 
there  are  at  least  three  kinds  of  ants — males,  females, 
and  workers.  The  males  and  females  have  wings  at 
first  and  the  workers  do  not.  When  they  settle  down 
into  nest  life  the  males  are  left  out ;  the  females,  or 
queens,  unhook  their  wings,  and  become  good  mothers 
and  home-keepers.  The  workers  attend  to  the  young, 


The  Reign  of  Land  Monsters. 

keep  the  nest  clean,  and  do  all  the  work.  But  with 
the  geologic  ants  all  the  members  of  the  colony  had 
wings.  They  probably  lived  a  savage  life  of  freedom, 
and  were  as  improvident  as  the  grasshoppers  and  but- 
terflies of  to-day. 

The  most  perfect  specimens  we  have  are  those  flies 
and  moths  which  were  enclosed  in  amber.  Amber  is 
only  fossil-tree  gum.  You  have  often  seen  a  clear, 
sticky  gum  oozing  out  of  cherry  and  peach  trees.  If 
you  notice  next  summer  you  will  very  likely  see  some 
unfortunate  insects  that  have  alighted  on  the  sticky 
stuff  and  are  caught  fast.  The  next  gum  that  oozes 
out  may  roll  over  the  poor  little  victim  and  enclose  it. 
As  long  as  the  amber  lasts,  the  insect  enclosed  will  re- 
main unchanged.  Most  of  the  fossil  insects  in  amber 
are  perfect,  except  their  legs,  which  have  been  broken 
in  the  struggle  to  free  themselves. 

Enormous  monsters  roamed  through  the  woods. 
Their  habits,  however,  were  generally  less  alarming 
than  their  looks,  for  most  of  them  were  herb-eating 
animals.  Great  sloths  as  large  as  an  elephant,  with 
terrible  paws  (Figs.  89  and  90)  and  gigantic  tails,  tore 
down  the  branches  of  trees  or  dug  up  eatable  roots. 
The  brains  of  these  animals  were  small  compared  to 


228 


The  Earth  in  Past  Ages. 


those  of  the  same  families  nowadays,  though  the  ani- 
mals themselves  were  so  much  larger.  There  were,  to 
be  sure,  some  lions,  tigers,  and  wolves  roaming  about 
in  search  of  prey,  but  most  of  the  animals  were  herb- 
eating,  as  are  the 
largest  of  the 
beasts  of  the  pres- 
ent day. 

Among  the  quad- 
rupeds we  see  the 
same  approach  to 
living  forms.  The 
forefathers  of  the 
horse,  deer,  ante- 
lope, elephant,  rhi- 
noceros, and  ta- 
pir appear.  The 
strange  reptilian 
birds  are  gone, 
and  in  their  places 
swallows  are  building  in  the  crevices  of  the  rocks; 
song-birds  fill  the  forests  with  their  happy  voices; 
parrots  call  from  one  tree  to  be  answered  from  an- 
other ;  cranes  and  flamingoes  wade  in  the  shallow  wa- 


Fig.  89. — SKELETON  OF  MEGATHERIUM. 
From  Hooker's  "  Mineralogy  and  Geology." 


The  Reign  of  Land  Monsters. 


229 


Fig.  90. — SKELETON  OF  MTLODON. 
From  Hooker's  "Mineralogy  and  Geology." 

ter,  seeking  their  food  ;  sand-grouse  and  the  ancestors 
of  our  domestic  fowls  scratch  around  with  their  broods. 
All  nature  is  making  ready  for  man,  who  will  appear 
in  the  next  period  of  the  world  as  the  crown  of  the 
Creator's  work. 


CHAPTER  XXII. 

THE  COMING   OF  MAN. 

THE  last  period  that  belongs  to  geology  was  the 
most  remarkable  in  the  history  of  the  earth  for  the 
great  changes  in  the  earth's  crust,  and  in  consequence 
of  this,  for  its  changes  in  climate. 

During  the  early  part  of  this  period,  for  some  un- 
known reason,  certain  parts  of  the  continents  lifted 
themselves  up  till  they  stood  one  or  two  thousand  feet 
higher  than  they  now  stand.  Later  on,  a  sinking  took 
place,  which  carried  some  parts  of  the  continents  as 
much  as  one  thousand  feet  below  where  they  are  to- 
day, and  after  that  they  began  again  to  rise  till  they 
reached  very  much  their  present  level. 

These  movements  caused,  of  course,  an  enormous 
alteration  of  climate,  and  the  changes  in  vegetable 
and  animal  life  which  accompany  variation  in  cli- 
mate. There  is  still  some  movement  going  on ;  some 
parts  of  America  are  rising,  while  other  parts  are 
slowly  sinking. 


The  Coming  of  Man.  231 

The  parts  of  America  and  Europe  that  rose  were 
all  towards  the  north.  The  mountain  chains  there 
and  the  high  plains  all  became  covered  with  a  thick 
sheet  of  ice,  which  moved,  like  the  glaciers  of  Switz- 
erland, to  the  lower  land,  grinding  and  wearing  down 
the  rocks  over  which  they  passed. 

You  may  very  naturally  ask,  How  can  we  know 
that  this  all  really  happened?  I  want  you  to  look 
back  at  the  chapter  on  the  work  of  the  Ice -king. 
You  will  find  there  that  all  glaciers  move,  and  as  they 
move  they  take  up  pieces  of  broken  rock  in  their  way ; 
these  freeze  into  the  under  side  of  the  moving  ice,  and 
scratch  and  score  the  bed-rock  over  which  it  passes, 
and  polish  off  their  own  corners  at  the  same  time. 

Strewed  all  over  the  northern  part  of  our  continent, 
on  the  tops  of  the  hills  as  well  as  in  the  bottoms  of 
the  valleys,  is  a  surface  soil  from  thirty  to  three  hun- 
dred feet  deep.  This  soil  is  made  up  of  stones,  gravel, 
sand,  and  earth,  which,  you  remember,  is  pulverized 
rock.  The  stones  are  irregular,  but  rounded  on  the 
corners,  scratched,  and  worn  exactly  like  the  stones 
that  are  found  beyond  the  end  of  a  glacier.  If  you 
dig  you  will  find  the  stones  becoming  more  worn 
and  scratched  as  you  go  down,  and  when  you  get  to 


232  The  Earth  m  Past  Ages. 

the  solid  rock  underneath  it  all,  that  too  is  scored  and 
polished,  all  in  one  direction,  as  only  a  heavy  body 
passing  over  it  and  grinding  it  down  could  do.  The 
very  top  stones  are  neither  scratched  nor  rounded, 
only  those  that  have  rubbed  against  one  another  in 
the  movement  of  the  glacier,  or  scratched  against  the 
bottom  rock. 

This  is  called  the  northern  drift ;  and  the  writing 
upon  the  wall  that  terrified  Belshazzar  so,  but  which 
Daniel  so  easily  read,  was  no  clearer  than  the  history 
of  its  progress  which  the  long  -  vanished  glacier  has 
left  written  upon  the  rocks.  If  more  proof  were 
needed,  it  is  here.  These  rocks  lying  loose  mixed 
with  the  soil  are  not  at  all  like  the  rock  beneath. 
Sometimes,  for  instance,  they  will  be  blocks  of  gran- 
ite, when  the  nearest  granite  bed-rock  is  a  hundred 
miles  away. 

In  the  Southern  States  there  is  no  such  drift.  The 
soil  there  is  often  mixed  with  stones,  but  they  are 
neither  scratched,  nor  scored,  nor  worn  down,  and 
they  are  usually  exactly  the  same  material  as  the  rock 
underneath  them. 

By  carefully  examining  the  drift  bowlders  we  find 
that  in  New  England  they  have  come  from  the  rocks 


The  Coming  of  Man.  233 

of  the  far  north-west ;  in  Ohio,  from  due  north ;  and 
in  Iowa,  from  north-east ;  that  is,  the  glaciers,  on  the 
testimony  of  the  rocks,  started  from  the  high  lands  of 
British  America,  and  spreading  out  both  east  and 
west,  moved  downward  and  outward  in  a  fan  shape 
towards  the  south.  The  distance  travelled  over  by 
this  sheet  of  ice  was  in  some  places  only  a  few  miles ; 
in  other  places,  some  hundreds  of  miles. 

These  glaciers  were  not  exactly  like  the  Swiss  gla- 
ciers, for  they  are  formed  and  move  in  a  warm  cli- 
mate, but  they  were  like  the  glaciers  of  Greenland. 
This  country,  you  know  from  your  geographies,  is  a 
great  peninsula  in  the  north-eastern  part  of  America. 
It  is  twelve  hundred  miles  long  by  about  five  hundred 
miles  wide ;  the  whole  country  is  covered  with  a  great 
ice  sheet  more  than  a  mile  thick.  This  sheet  moves 
southward  and  towards  the  sea,  forced  onward  by  the 
weight  of  snow  and  ice  on  the  northern  and  high  land 
part,  which  each  winter's  freeze  makes  heavier.  The 
solid  sheet  only  separates  into  distinct  glaciers  when 
it  reaches  the  ocean.  As  these  move  off  the  coast, 
the  waves  wear  them,  and  they  finally  break  off,  and 
with  a  thundering  noise  go  splashing  into  the  sea  and 
float  away  as  icebergs. 


234  The  Earth  in  Past  Ages. 

Just  so  New  England,  Ohio,  Illinois,  Indiana,  and 
Iowa  were  covered  with  a  great  ice  sheet  that  moved 
southward,  scouring  and  polishing  the  bed-rock,  and 
gouging  out  lake -beds.  From  its  southern  margin 
the  ice  sheet  "stretched  out  icy  fingers"  down  the 
valleys  of  the  Hudson,  the  Susquehanna,  and  other 
rivers,  and  passed  away  as  icebergs  when  they  reached 
the  sea. 

After  this  came  the  time  when  the  continents  be- 
gan to  sink.  Down,  down  they  went,  so  slowly  that 
we  cannot  conceive  of  it  as  motion,  till  the  land  lay 
in  places  two  or  three  thousand  feet  below  where  it 
had  been  in  the  ice  period,  and  one  thousand  feet  be- 
low the  present  level.  The  water,  of  course,  rushed 
in,  filling  the  low  lands,  and  turning  them  into  lakes 
and  inland  seas.  Above  the  drift  there  are  plainly  to 
be  seen  old  lake-margins  and  signs  of  flood  proving 
this  point.  Europe  had  very  much  the  same  experi- 
ence as  America  in  the  rising  and  falling  of  certain 
parts  of  the  continent. 

During  this  age  there  were  immense  numbers  ol 
mammals.  Their  skeletons  are  to  be  found  in  old  sea- 
beaches  and  lake  -  margins,  where  they  were  stranded 
and  covered  over  with  mud  and  sand  ;  in  marshes  ancl 


The  Coming  of  Man. 


235 


Fig.  91. — THE  IRISH  ELK  COMPARED  WITH  MAN. 
From  Wiuchell's  "Sketches  of  Creation." 

bogs,  where  they  had  been  mired  when  seeking  for 
food,  and  preserved  by  the  bog- water  (Fig.  91) ;  and 
in  frozen  ground  and  ice-banks,  where  some  of  them 
have  been  preserved  to  the  present  century. 

Do  you  remember  about  the  limestone  caverns — 
great  holes  worn  out  in  the  midst  of  the  rocks  by  the 
dripping  water  ?  Look  back  to  Chapter  III.,  at  the 


236  The  Earth  in  Past  Ages. 

picture  of  Luray,  if  you  have  forgotten.  These  caves 
seem  to  have  been  the  homes  of  myriads  of  animals  at 
this  time ;  hundreds  of  skeletons  and  bones  are  found 
in  them — elephants  and  bears,  elks,  horses,  and  oxen, 
hyenas,  lions,  and  tigers  in  a  jumble,  covered  over  with 
the  stalagmites  from  the  drippings  of  the  cave.  It  is 
generally  supposed,  from  the  gnawed  state  of  some  of 
the  bones,  that  these  caves  were  the  homes  of  the 
lions,  bears,  and  hyenas,  and  that  they  dragged  their 
prey  in  here  to  devour  them.  It  may  have  been  that 
others  were  washed  in  by  the  water  which  overlaid 
them  in  many  cases  with  mud  and  sand. 

The  animals  found  in  bogs  were  almost  always  herb- 
eating  creatures,  who  evidently  went  there  for  food, 
and  sank  in  and  were  drowned. 

The  most  wonderful  specimens  which  have  been 
found  belonging  to  this  era  were  those  that  had  been 
in  some  way  enclosed  in  ice  and  frozen  up,  and  have 
come  down  to  modern  times  entire,  not  mere  skeletons, 
but  with  flesh  and  skin,  tusks  and  wool,  all  preserved. 
The  creature  so  frozen  up  is  called  the  hairy  mammoth 
(Fig.  92),  and  this  is  the  way  he  was  found  : 

In  1799  an  Asiatic  chief,  who  used  to  collect  the 
tusks  found  in  the  northern  part  of  Siberia  for  sale. 


The  Coming  of  Man. 


237 


Fig.  92. — THE  HAIRY  MAMMOTH. 
From  Winchell's  "Sketches  of  Creation." 

observed  a  queer  dark  mass  in  a  block  of  ice.  Each 
year  on  his  hunts,  as  the  ice  broke  away,  he  saw  more 
and  more  of  the  body  of  a  mammoth  exposed ;  final- 
ly, at  the  end  of  five  years,  the  ice  melted  so  much 
that  the  body  rolled  out  upon  a  sand-bank  below.  The 
hunter  cut  off  the  tusks,  which  he  sold  for  about  forty 
dollars.  The  animal  was  a  mammoth,  covered  with 


238  The  Earth  in  Past  Ages. 

reddish  wool  and  long  coarse  hair,  and  with  a  heavy 
mane.  The  flesh,  after  its  burial  in  the  ice  for  un- 
counted thousands  of  years,  was  fresh  enough  for  the 
dogs  to  devour  it  eagerly.  When  it  was  found  by  Mr. 
Adams,  who  knew  the  value  of  the  creature  as  a  speci- 
men, he  says  that  the  ground  around  it  was  trampled 
by  the  wild  beasts — white  bears,  wolves,  and  foxes — 
which  had  come  to  feed  upon  the  flesh.  Mr.  Adams 
got  the  bones  out  of  the  ice,  bought  back  the  tusks, 
and  brought  the  whole  thing  over  seven  thousand 
miles  to  St.  Petersburg,  where  its  skeleton  now  is. 
He  says  he  collected  more  than  thirty-six  pounds  of 
hair  and  wool,  which  had  been  trampled  into  the 
ground  by  the  animals  that  came  to  feed  on  the  flesh. 
The  skin  still  remains  on  its  head,  and  some  of  the 
mane  on  its  neck.  Other  specimens  have  been  found 
in  the  ice,  but  this  one  is  the  best  preserved. 

The  mastodon,  another  member  of  the  elephant  fam- 
ily, occurs  in  America.  The  mastodon  was  one  of  the 
two  largest  land  animals ;  it  was  fourteen  feet  high, 
and  twenty-five  feet  long,  including  its  tusks.  Along 
with  these  mighty  elephants  and  the  cave  animals 
man  appeared  upon  the  earth  (Fig.  93).  He  may  have 
come  earlier,  but  that  is  not  perfectly  certain.  In  the 


The  Coming  of  Man.  241 

caves  human  bones  are  mixed  with  those  of  the  cave 
lion  and  bear ;  together  they  have  been  covered  over 
and  preserved.  Stone  implements,  and  piles  of  what 
are  called  kitchen-middens,  also  occur :  these  are  refuse 
of  food,  piles  of  oyster-shells  that  have  been  opened, 
and  other  things  that  prove  conclusively  that  they  are 
the  work  of  men. 

But  the  strongest  proof  of  all  that  human  beings 
lived  at  the  same  time  as  the  cave  animals  and  mam- 
moths is  that  in  a  cave  in  France  several  smooth  pieces 
of  bone,  with  rough  pictures  of  the  animals  scratched 
upon  them  with  some  sharp-pointed  instrument,  have 
been  found.  In  Figure  92  you  see  such  a  picture  of 
the  mammoth  drawn  by  primeval  or  early  man. 

This  age  I  have  called  the  Coming  of  Man,  and 
not  the  Eeign  of  Man.  He  has  only  appeared  upon 
the  scene,  but  he  has  not  yet  gained  the  mastery 
over  the  brutes ;  he  is  still  a  savage,  with  only  the 
rudest  and  simplest  arts,  but  he  is  a  man — as  truly  a 
member  of  the  human  race  as  any  who  have  come 
after  him.  But  it  is  as  the  promise  of  the  reign  to 
come  that  he  means  anything,  rather  than  that  he  is, 
for  some  time  to  come,  to  be  fully  established  as  the 
lord  of  creation. 

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ought  to  know.  These  embrace  diagrams,  sketch 
maps,  and  graphic  representations  of  the  ratio  of 
the  important  productions  of  the  United  States  to 
those  of  the  rest  of  the  world.  Of  special 
importance  is  the  miniature  sketch  map  of  the 
United  States  in  connection  with  the  large  study 
map  of  each  of  the  sections  of  our  country,  thus 
preventing  the  pupil  from  forming  an  incorrect 
idea  of  the  size  of  the  section  under  considera- 
tion. The  maps  are  conspicuous  for  their  beauty 
and  distinctness.  The  illustrations  are  unusually 
artistic  and  attractive. 


COMPANY 

[S.  ,08]  (UNIVER8ITy 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


AN     INITIAL    FINE    OF    25    CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  5O  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $1.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


MAR  19  1933 
7  1938 


NOV 


JUN9  "61 

REC'D  LD 

JUN 


/66 


196435 


